[
  {
    "sku": "430311XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430311XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 55,
    "D_mm": 120,
    "B_mm": 70,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 295,
    "static_load_kN": 360,
    "fatigue_load_limit_kN": 43.5,
    "limiting_speed_rpm": 2700,
    "max_rpm": 2700,
    "speed_oil_rpm": 3700,
    "weight_g": 3570,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-430311XU at 55 mm bore, 120 mm OD and 70 mm overall width, with a grease limiting speed of 2,700 r/min and an oil ceiling of 3,700 r/min. Reading the designation: the last two digits 11 are the bore code, ×5 = 55 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. Axial capacity is bidirectional because the rows are opposed: 4T-430311XU locates the shaft in both directions with C0 360 kN behind the static check of the more heavily loaded row. TDO construction means the two cone assemblies of 4T-430311XU face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 55 mm shaft. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-430311XU's locating position.",
    "applications": [
      "rolling-mill work-roll and backup auxiliary positions",
      "crane travel and hoist drum shafts",
      "mining conveyor drive and head pulleys",
      "paper-machine roll and press supports"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "Gearbox positions of this 55 mm class rely on the preset clearance of 4T-430311XU; shimming or nut-tightening the unit like a single-row pair overruns the factory setting and runs the rows hot.",
      "The 430 light plan keeps 4T-430311XU narrower and faster than the 432 heavy execution of the same 55 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "At inspection do not mix the cone assemblies of 4T-430311XU with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 120 mm OD clamping uniformly around the circumference.",
      "Grease packs must leave free volume across the 70 mm width; over-greasing a unit churning near the 3,700 r/min oil-band speed raises temperature and expels the grease.",
      "The 295/360 kN ratings and 43.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430311XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430311XU?",
        "a": "4T-430311XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 55 mm bore, 120 mm outside diameter and 70 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 295 kN, C0 360 kN, Cu 43.5 kN, grease limiting speed 2,700 r/min, oil speed 3,700 r/min, mass about 3.57 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 55 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430311XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430311XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 70 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430311XU mean?",
        "a": "Suffix reading on 430311XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430311XU list two speeds, 2,700 and 3,700 r/min?",
        "a": "The lower figure, 2,700 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430311XU at 3,700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430311XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430311xu",
      "4t-430311xu",
      "430311XU",
      "4T-430311XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432311U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432311U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 55,
    "D_mm": 120,
    "B_mm": 97,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 410,
    "static_load_kN": 550,
    "fatigue_load_limit_kN": 67,
    "limiting_speed_rpm": 2700,
    "max_rpm": 2700,
    "speed_oil_rpm": 3700,
    "weight_g": 5050,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-432311U belongs to the heavy-duty 432-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Reading the designation: the last two digits 11 are the bore code, ×5 = 55 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. Axial capacity is bidirectional because the rows are opposed: 4T-432311U locates the shaft in both directions with C0 550 kN behind the static check of the more heavily loaded row. TDO construction means the two cone assemblies of 4T-432311U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 55 mm shaft. The open unit carries no seals; the housing of 4T-432311U must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "paper-machine roll and press supports",
      "extruder and mixer drive shafts",
      "construction-equipment swing and pivot shafts",
      "industrial gearbox shafts in a single locating position"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Gearbox positions of this 55 mm class rely on the preset clearance of 4T-432311U; shimming or nut-tightening the unit like a single-row pair overruns the factory setting and runs the rows hot.",
      "The 432 heavy plan gives 4T-432311U its 97 mm width and 410 kN rating at the 55 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 67 kN Cu.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 97 mm width, load spread and clearance logic of 4T-432311U are unit-specific.",
      "Open 4T-432311U units have no seals: the housing must seal both rows or the 2,700 r/min grease figure is meaningless once contamination enters.",
      "An unloaded 4T-432311U near 2,700 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 410/550 kN ratings and 67 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432311U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432311U?",
        "a": "4T-432311U is a double-row tapered roller bearing of TDO (back-to-back) construction: 55 mm bore, 120 mm outside diameter and 97 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 410 kN, C0 550 kN, Cu 67 kN, grease limiting speed 2,700 r/min, oil speed 3,700 r/min, mass about 5.05 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 55 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432311U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432311U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 97 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432311U mean?",
        "a": "Suffix reading on 432311U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432311U list two speeds, 2,700 and 3,700 r/min?",
        "a": "The lower figure, 2,700 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432311U at 3,700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432311U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432311u",
      "4t-432311u",
      "432311U",
      "4T-432311U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430212X",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430212X",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 53,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 199,
    "static_load_kN": 249,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "speed_oil_rpm": 3800,
    "weight_g": 1990,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430212X is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 60×110×53 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-430212X integrates both rows in one article: the 53 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. 2203E prints no Cu fatigue load limit for 4T-430212X (the dash in the Cu column); life work for this size uses the 199/249 kN C/C0 pair directly. TDO construction means the two cone assemblies of 4T-430212X face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 60 mm shaft. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-430212X's locating position.",
    "applications": [
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "Mount the 60 mm unit by induction heating (max 120 °C); at 1.99 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430212X narrower and faster than the 432 heavy execution of the same 60 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The internal clearance of 4T-430212X is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 53 mm width, load spread and clearance logic of 4T-430212X are unit-specific.",
      "An unloaded 4T-430212X near 2,800 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 199/249 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430212X; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430212X?",
        "a": "4T-430212X is a double-row tapered roller bearing of TDO (back-to-back) construction: 60 mm bore, 110 mm outside diameter and 53 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 199 kN, C0 249 kN (2203E prints a dash for Cu on this size), grease limiting speed 2,800 r/min, oil speed 3,800 r/min, mass about 1.99 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 60 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430212X belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430212X be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 53 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430212X mean?",
        "a": "Suffix reading on 430212X: X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430212X list two speeds, 2,800 and 3,800 r/min?",
        "a": "The lower figure, 2,800 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430212X at 3,800 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430212X",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430212x",
      "4t-430212x",
      "430212X",
      "4T-430212X"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432212U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432212U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 66,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 247,
    "static_load_kN": 330,
    "fatigue_load_limit_kN": 40,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "speed_oil_rpm": 3800,
    "weight_g": 2490,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-432212U at 60 mm bore, 110 mm OD and 66 mm overall width, with a grease limiting speed of 2,800 r/min and an oil ceiling of 3,800 r/min. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 60 mm bore the 432 execution carries a wider, heavier section than the 430. Grease relubrication at the 2,800 r/min limiting speed must reach both roller rows; sustaining 3,800 r/min needs an oil supply with defined flow through the double cup. TDO construction means the two cone assemblies of 4T-432212U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 60 mm shaft. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-432212U.",
    "applications": [
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 60 mm unit by induction heating (max 120 °C); at 2.49 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432212U its 66 mm width and 247 kN rating at the 60 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 40 kN Cu.",
      "An unloaded 4T-432212U near 2,800 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-432212U feeds the two roller complements evenly; a single-side feed starves the far row.",
      "An unloaded 4T-432212U near 2,800 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 247/330 kN ratings and 40 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432212U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432212U?",
        "a": "4T-432212U is a double-row tapered roller bearing of TDO (back-to-back) construction: 60 mm bore, 110 mm outside diameter and 66 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 247 kN, C0 330 kN, Cu 40 kN, grease limiting speed 2,800 r/min, oil speed 3,800 r/min, mass about 2.49 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 60 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432212U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432212U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 66 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432212U mean?",
        "a": "Suffix reading on 432212U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432212U list two speeds, 2,800 and 3,800 r/min?",
        "a": "The lower figure, 2,800 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432212U at 3,800 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432212U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432212u",
      "4t-432212u",
      "432212U",
      "4T-432212U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430312DX",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430312DX",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 60,
    "D_mm": 130,
    "B_mm": 74,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 286,
    "static_load_kN": 350,
    "limiting_speed_rpm": 2200,
    "max_rpm": 2200,
    "speed_oil_rpm": 2900,
    "weight_g": 4300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 60 mm shaft needing a compact two-direction thrust location, NTN lists 4T-430312DX, a TDO double-row 4T unit of 286 kN C and 350 kN C0 in the light-duty 430-family TDO double-row series. Suffix reading on 430312DX: X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles. Catalogue mass of 4T-430312DX is 4.3 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. TDO construction means the two cone assemblies of 4T-430312DX face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 60 mm shaft. With a rotating shaft a k5/m5 seat on the 60 mm journal and a located cup in the housing are typical practice for 4T-430312DX.",
    "applications": [
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "Mount the 60 mm unit by induction heating (max 120 °C); at 4.3 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430312DX narrower and faster than the 432 heavy execution of the same 60 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 130 mm OD clamping uniformly around the circumference.",
      "The 35.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-430312DX or the cones bottom out on the radius.",
      "Open 4T-430312DX units have no seals: the housing must seal both rows or the 2,200 r/min grease figure is meaningless once contamination enters.",
      "The 286/350 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430312DX; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430312DX?",
        "a": "4T-430312DX is a double-row tapered roller bearing of TDO (back-to-back) construction: 60 mm bore, 130 mm outside diameter and 74 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 286 kN, C0 350 kN (2203E prints a dash for Cu on this size), grease limiting speed 2,200 r/min, oil speed 2,900 r/min, mass about 4.3 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 60 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430312DX belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430312DX be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 74 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430312DX mean?",
        "a": "Suffix reading on 430312DX: X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430312DX list two speeds, 2,200 and 2,900 r/min?",
        "a": "The lower figure, 2,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430312DX at 2,900 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430312DX",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430312dx",
      "4t-430312dx",
      "430312DX",
      "4T-430312DX"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430312U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430312U",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 60,
    "D_mm": 130,
    "B_mm": 74,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 340,
    "static_load_kN": 420,
    "fatigue_load_limit_kN": 51,
    "limiting_speed_rpm": 2500,
    "max_rpm": 2500,
    "speed_oil_rpm": 3400,
    "weight_g": 4310,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 60 mm shaft position as 4T-430312U: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 74 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-430312U integrates both rows in one article: the 74 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The fatigue load limit Cu printed for 4T-430312U is 51 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. Because the unit is preset, mounting 4T-430312U resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-430312U.",
    "applications": [
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "Mount the 60 mm unit by induction heating (max 120 °C); at 4.31 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430312U narrower and faster than the 432 heavy execution of the same 60 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 130 mm OD clamping uniformly around the circumference.",
      "At inspection do not mix the cone assemblies of 4T-430312U with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "At inspection do not mix the cone assemblies of 4T-430312U with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 340/420 kN ratings and 51 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430312U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430312U?",
        "a": "4T-430312U is a double-row tapered roller bearing of TDO (back-to-back) construction: 60 mm bore, 130 mm outside diameter and 74 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 340 kN, C0 420 kN, Cu 51 kN, grease limiting speed 2,500 r/min, oil speed 3,400 r/min, mass about 4.31 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 60 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430312U belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430312U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 74 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430312U mean?",
        "a": "Suffix reading on 430312U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430312U list two speeds, 2,500 and 3,400 r/min?",
        "a": "The lower figure, 2,500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430312U at 3,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430312U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430312u",
      "4t-430312u",
      "430312U",
      "4T-430312U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432312U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432312U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 60,
    "D_mm": 130,
    "B_mm": 104,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 465,
    "static_load_kN": 625,
    "fatigue_load_limit_kN": 76.5,
    "limiting_speed_rpm": 2500,
    "max_rpm": 2500,
    "speed_oil_rpm": 3400,
    "weight_g": 6390,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 60 mm shaft position as 4T-432312U: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 104 mm. Suffix reading on 432312U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles. Selection: C 465 kN against C0 625 kN gives a C0/C ratio of 1.34; the two rows of 4T-432312U share the combined load as one bearing position. TDO construction means the two cone assemblies of 4T-432312U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 60 mm shaft. Mount 4T-432312U as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 60 mm unit by induction heating (max 120 °C); at 6.39 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432312U its 104 mm width and 465 kN rating at the 60 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 76.5 kN Cu.",
      "Grease packs must leave free volume across the 104 mm width; over-greasing a unit churning near the 3,400 r/min oil-band speed raises temperature and expels the grease.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 104 mm width, load spread and clearance logic of 4T-432312U are unit-specific.",
      "Order by the full 432312U code including suffixes — U, X, DX, E1 and UTG variants share the 60 mm bore but are different articles with different internal geometry.",
      "The 465/625 kN ratings and 76.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432312U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432312U?",
        "a": "4T-432312U is a double-row tapered roller bearing of TDO (back-to-back) construction: 60 mm bore, 130 mm outside diameter and 104 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 465 kN, C0 625 kN, Cu 76.5 kN, grease limiting speed 2,500 r/min, oil speed 3,400 r/min, mass about 6.39 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 60 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432312U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432312U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 104 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432312U mean?",
        "a": "Suffix reading on 432312U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432312U list two speeds, 2,500 and 3,400 r/min?",
        "a": "The lower figure, 2,500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432312U at 3,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432312U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432312u",
      "4t-432312u",
      "432312U",
      "4T-432312U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430213X",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430213X",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 56,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 234,
    "static_load_kN": 295,
    "limiting_speed_rpm": 2600,
    "max_rpm": 2600,
    "speed_oil_rpm": 3500,
    "weight_g": 2560,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430213X is the NTN 4T catalogue entry for a 65×120×56 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 430213X reads accordingly. Speed planning uses both catalogue columns: grease 2,600 r/min is the mechanical ceiling, oil 3,500 r/min with oil lubrication — a 900 r/min margin at this size. TDO construction means the two cone assemblies of 4T-430213X face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 65 mm shaft. At 234 kN C the unit offers about 3.6 kN per millimetre of the 65 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 3,500 r/min.",
    "applications": [
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "Mount the 65 mm unit by induction heating (max 120 °C); at 2.56 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430213X narrower and faster than the 432 heavy execution of the same 65 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 27.5 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-430213X or the cones bottom out on the radius.",
      "Order by the full 430213X code including suffixes — U, X, DX, E1 and UTG variants share the 65 mm bore but are different articles with different internal geometry.",
      "Order by the full 430213X code including suffixes — U, X, DX, E1 and UTG variants share the 65 mm bore but are different articles with different internal geometry.",
      "The 234/295 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430213X; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430213X?",
        "a": "4T-430213X is a double-row tapered roller bearing of TDO (back-to-back) construction: 65 mm bore, 120 mm outside diameter and 56 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 234 kN, C0 295 kN (2203E prints a dash for Cu on this size), grease limiting speed 2,600 r/min, oil speed 3,500 r/min, mass about 2.56 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 65 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430213X belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430213X be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 56 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430213X mean?",
        "a": "Suffix reading on 430213X: X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430213X list two speeds, 2,600 and 3,500 r/min?",
        "a": "The lower figure, 2,600 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430213X at 3,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430213X",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430213x",
      "4t-430213x",
      "430213X",
      "4T-430213X"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432213U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432213U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 73,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 300,
    "static_load_kN": 410,
    "fatigue_load_limit_kN": 50,
    "limiting_speed_rpm": 2600,
    "max_rpm": 2600,
    "speed_oil_rpm": 3500,
    "weight_g": 3410,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-432213U is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 65×120×73 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-432213U integrates both rows in one article: the 73 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Axial capacity is bidirectional because the rows are opposed: 4T-432213U locates the shaft in both directions with C0 410 kN behind the static check of the more heavily loaded row. TDO construction means the two cone assemblies of 4T-432213U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 65 mm shaft. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-432213U's locating position.",
    "applications": [
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 65 mm unit by induction heating (max 120 °C); at 3.41 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432213U its 73 mm width and 300 kN rating at the 65 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 50 kN Cu.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 120 mm OD clamping uniformly around the circumference.",
      "Open 4T-432213U units have no seals: the housing must seal both rows or the 2,600 r/min grease figure is meaningless once contamination enters.",
      "Order by the full 432213U code including suffixes — U, X, DX, E1 and UTG variants share the 65 mm bore but are different articles with different internal geometry.",
      "The 300/410 kN ratings and 50 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432213U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432213U?",
        "a": "4T-432213U is a double-row tapered roller bearing of TDO (back-to-back) construction: 65 mm bore, 120 mm outside diameter and 73 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 300 kN, C0 410 kN, Cu 50 kN, grease limiting speed 2,600 r/min, oil speed 3,500 r/min, mass about 3.41 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 65 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432213U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432213U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 73 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432213U mean?",
        "a": "Suffix reading on 432213U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432213U list two speeds, 2,600 and 3,500 r/min?",
        "a": "The lower figure, 2,600 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432213U at 3,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432213U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432213u",
      "4t-432213u",
      "432213U",
      "4T-432213U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430313DX",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430313DX",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 79,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 330,
    "static_load_kN": 410,
    "limiting_speed_rpm": 2000,
    "max_rpm": 2000,
    "speed_oil_rpm": 2700,
    "weight_g": 5260,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430313DX is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 65×140×79 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-430313DX integrates both rows in one article: the 79 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Axial capacity is bidirectional because the rows are opposed: 4T-430313DX locates the shaft in both directions with C0 410 kN behind the static check of the more heavily loaded row. TDO construction means the two cone assemblies of 4T-430313DX face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 65 mm shaft. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-430313DX.",
    "applications": [
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "Mount the 65 mm unit by induction heating (max 120 °C); at 5.26 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430313DX narrower and faster than the 432 heavy execution of the same 65 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 330 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "An unloaded 4T-430313DX near 2,000 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 79 mm width, load spread and clearance logic of 4T-430313DX are unit-specific.",
      "The 330/410 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430313DX; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430313DX?",
        "a": "4T-430313DX is a double-row tapered roller bearing of TDO (back-to-back) construction: 65 mm bore, 140 mm outside diameter and 79 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 330 kN, C0 410 kN (2203E prints a dash for Cu on this size), grease limiting speed 2,000 r/min, oil speed 2,700 r/min, mass about 5.26 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 65 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430313DX belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430313DX be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 79 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430313DX mean?",
        "a": "Suffix reading on 430313DX: X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430313DX list two speeds, 2,000 and 2,700 r/min?",
        "a": "The lower figure, 2,000 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430313DX at 2,700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430313DX",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430313dx",
      "4t-430313dx",
      "430313DX",
      "4T-430313DX"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430313XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430313XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 79,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 385,
    "static_load_kN": 475,
    "fatigue_load_limit_kN": 57.5,
    "limiting_speed_rpm": 2300,
    "max_rpm": 2300,
    "speed_oil_rpm": 3100,
    "weight_g": 5410,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-430313XU denotes the light-duty 430-family TDO double-row series — a 65 mm bore double-row tapered unit rated 385 kN basic dynamic and 475 kN static. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 430313XU reads accordingly. Double-row capacity is not twice a single-row bearing: the printed 385 kN C already accounts for load sharing between the two rows of 4T-430313XU, so apply it directly in the L10 calculation. The internal clearance of 4T-430313XU is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 79 mm overall width is the finished dimension. At 385 kN C the unit offers about 5.9 kN per millimetre of the 65 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 3,100 r/min.",
    "applications": [
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "Mount the 65 mm unit by induction heating (max 120 °C); at 5.41 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430313XU narrower and faster than the 432 heavy execution of the same 65 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 385 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "An unloaded 4T-430313XU near 2,300 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Open 4T-430313XU units have no seals: the housing must seal both rows or the 2,300 r/min grease figure is meaningless once contamination enters.",
      "The 385/475 kN ratings and 57.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430313XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430313XU?",
        "a": "4T-430313XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 65 mm bore, 140 mm outside diameter and 79 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 385 kN, C0 475 kN, Cu 57.5 kN, grease limiting speed 2,300 r/min, oil speed 3,100 r/min, mass about 5.41 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 65 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430313XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430313XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 79 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430313XU mean?",
        "a": "Suffix reading on 430313XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430313XU list two speeds, 2,300 and 3,100 r/min?",
        "a": "The lower figure, 2,300 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430313XU at 3,100 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430313XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430313xu",
      "4t-430313xu",
      "430313XU",
      "4T-430313XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432313U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432313U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 108,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 520,
    "static_load_kN": 700,
    "fatigue_load_limit_kN": 85,
    "limiting_speed_rpm": 2300,
    "max_rpm": 2300,
    "speed_oil_rpm": 3100,
    "weight_g": 7550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 65 mm shaft needing a compact two-direction thrust location, NTN lists 4T-432313U, a TDO double-row 4T unit of 520 kN C and 700 kN C0 in the heavy-duty 432-family TDO double-row series. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 65 mm bore the 432 execution carries a wider, heavier section than the 430. The fatigue load limit Cu printed for 4T-432313U is 85 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-432313U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 65 mm shaft. With a rotating shaft a k5/m5 seat on the 65 mm journal and a located cup in the housing are typical practice for 4T-432313U.",
    "applications": [
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 65 mm unit by induction heating (max 120 °C); at 7.55 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432313U its 108 mm width and 520 kN rating at the 65 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 85 kN Cu.",
      "At inspection do not mix the cone assemblies of 4T-432313U with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Order by the full 432313U code including suffixes — U, X, DX, E1 and UTG variants share the 65 mm bore but are different articles with different internal geometry.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-432313U feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 520/700 kN ratings and 85 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432313U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432313U?",
        "a": "4T-432313U is a double-row tapered roller bearing of TDO (back-to-back) construction: 65 mm bore, 140 mm outside diameter and 108 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 520 kN, C0 700 kN, Cu 85 kN, grease limiting speed 2,300 r/min, oil speed 3,100 r/min, mass about 7.55 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 65 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432313U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432313U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 108 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432313U mean?",
        "a": "Suffix reading on 432313U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432313U list two speeds, 2,300 and 3,100 r/min?",
        "a": "The lower figure, 2,300 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432313U at 3,100 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432313U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432313u",
      "4t-432313u",
      "432313U",
      "4T-432313U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430214",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430214",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 70,
    "D_mm": 125,
    "B_mm": 59,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 250,
    "static_load_kN": 325,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "speed_oil_rpm": 3200,
    "weight_g": 2830,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 70 mm shaft position as 4T-430214: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 59 mm. Reading the designation: the last two digits 14 are the bore code, ×5 = 70 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. The 27.5 mm radial section over the 70 mm bore carries two roller rows across the 59 mm width; abutment shoulders must clear both cone bores and the double-cup OD. The internal clearance of 4T-430214 is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 59 mm overall width is the finished dimension. At 250 kN C the unit offers about 3.6 kN per millimetre of the 70 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 3,200 r/min.",
    "applications": [
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "Mount the 70 mm unit by induction heating (max 120 °C); at 2.83 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430214 narrower and faster than the 432 heavy execution of the same 70 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 59 mm width, load spread and clearance logic of 4T-430214 are unit-specific.",
      "An unloaded 4T-430214 near 2,400 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Open 4T-430214 units have no seals: the housing must seal both rows or the 2,400 r/min grease figure is meaningless once contamination enters.",
      "The 250/325 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430214; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430214?",
        "a": "4T-430214 is a double-row tapered roller bearing of TDO (back-to-back) construction: 70 mm bore, 125 mm outside diameter and 59 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 250 kN, C0 325 kN (2203E prints a dash for Cu on this size), grease limiting speed 2,400 r/min, oil speed 3,200 r/min, mass about 2.83 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 70 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430214 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430214 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 59 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430214 mean?",
        "a": "With no letter suffix, 430214 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-430214 list two speeds, 2,400 and 3,200 r/min?",
        "a": "The lower figure, 2,400 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430214 at 3,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430214",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-430214",
      "430214",
      "4T-430214"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432214U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432214U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 70,
    "D_mm": 125,
    "B_mm": 74,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 315,
    "static_load_kN": 440,
    "fatigue_load_limit_kN": 53.5,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "speed_oil_rpm": 3200,
    "weight_g": 3650,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-432214U is the NTN 4T catalogue entry for a 70×125×74 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 432214U reads accordingly. Selection: C 315 kN against C0 440 kN gives a C0/C ratio of 1.40; the two rows of 4T-432214U share the combined load as one bearing position. TDO construction means the two cone assemblies of 4T-432214U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 70 mm shaft. At 315 kN C the unit offers about 4.5 kN per millimetre of the 70 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 3,200 r/min.",
    "applications": [
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 70 mm unit by induction heating (max 120 °C); at 3.65 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432214U its 74 mm width and 315 kN rating at the 70 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 53.5 kN Cu.",
      "Open 4T-432214U units have no seals: the housing must seal both rows or the 2,400 r/min grease figure is meaningless once contamination enters.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 74 mm width, load spread and clearance logic of 4T-432214U are unit-specific.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-432214U feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 315/440 kN ratings and 53.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432214U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432214U?",
        "a": "4T-432214U is a double-row tapered roller bearing of TDO (back-to-back) construction: 70 mm bore, 125 mm outside diameter and 74 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 315 kN, C0 440 kN, Cu 53.5 kN, grease limiting speed 2,400 r/min, oil speed 3,200 r/min, mass about 3.65 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 70 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432214U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432214U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 74 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432214U mean?",
        "a": "Suffix reading on 432214U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432214U list two speeds, 2,400 and 3,200 r/min?",
        "a": "The lower figure, 2,400 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432214U at 3,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432214U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432214u",
      "4t-432214u",
      "432214U",
      "4T-432214U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430314DX",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430314DX",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 70,
    "D_mm": 150,
    "B_mm": 83,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 365,
    "static_load_kN": 460,
    "limiting_speed_rpm": 1900,
    "max_rpm": 1900,
    "speed_oil_rpm": 2500,
    "weight_g": 6320,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 70 mm shaft position as 4T-430314DX: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 83 mm. Reading the designation: the last two digits 14 are the bore code, ×5 = 70 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. Speed planning uses both catalogue columns: grease 1,900 r/min is the mechanical ceiling, oil 2,500 r/min with oil lubrication — a 600 r/min margin at this size. The internal clearance of 4T-430314DX is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 83 mm overall width is the finished dimension. Induction heating to max 120 °C is the standard fitting method at this 70 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "Mount the 70 mm unit by induction heating (max 120 °C); at 6.32 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430314DX narrower and faster than the 432 heavy execution of the same 70 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-430314DX feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The internal clearance of 4T-430314DX is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "At inspection do not mix the cone assemblies of 4T-430314DX with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 365/460 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430314DX; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430314DX?",
        "a": "4T-430314DX is a double-row tapered roller bearing of TDO (back-to-back) construction: 70 mm bore, 150 mm outside diameter and 83 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 365 kN, C0 460 kN (2203E prints a dash for Cu on this size), grease limiting speed 1,900 r/min, oil speed 2,500 r/min, mass about 6.32 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 70 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430314DX belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430314DX be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 83 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430314DX mean?",
        "a": "Suffix reading on 430314DX: X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430314DX list two speeds, 1,900 and 2,500 r/min?",
        "a": "The lower figure, 1,900 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430314DX at 2,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430314DX",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430314dx",
      "4t-430314dx",
      "430314DX",
      "4T-430314DX"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430314XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430314XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 70,
    "D_mm": 150,
    "B_mm": 83,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 435,
    "static_load_kN": 545,
    "fatigue_load_limit_kN": 64,
    "limiting_speed_rpm": 2200,
    "max_rpm": 2200,
    "speed_oil_rpm": 2900,
    "weight_g": 6530,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430314XU is the NTN 4T catalogue entry for a 70×150×83 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Suffix reading on 430314XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles. The fatigue load limit Cu printed for 4T-430314XU is 64 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. The internal clearance of 4T-430314XU is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 83 mm overall width is the finished dimension. Axial clamping of the double cup must be uniform around the 150 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "Mount the 70 mm unit by induction heating (max 120 °C); at 6.53 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430314XU narrower and faster than the 432 heavy execution of the same 70 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-430314XU feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Grease packs must leave free volume across the 83 mm width; over-greasing a unit churning near the 2,900 r/min oil-band speed raises temperature and expels the grease.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 83 mm width, load spread and clearance logic of 4T-430314XU are unit-specific.",
      "The 435/545 kN ratings and 64 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430314XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430314XU?",
        "a": "4T-430314XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 70 mm bore, 150 mm outside diameter and 83 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 435 kN, C0 545 kN, Cu 64 kN, grease limiting speed 2,200 r/min, oil speed 2,900 r/min, mass about 6.53 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 70 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430314XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430314XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 83 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430314XU mean?",
        "a": "Suffix reading on 430314XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430314XU list two speeds, 2,200 and 2,900 r/min?",
        "a": "The lower figure, 2,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430314XU at 2,900 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430314XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430314xu",
      "4t-430314xu",
      "430314XU",
      "4T-430314XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432314U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432314U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 70,
    "D_mm": 150,
    "B_mm": 116,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 590,
    "static_load_kN": 805,
    "fatigue_load_limit_kN": 95.5,
    "limiting_speed_rpm": 2200,
    "max_rpm": 2200,
    "speed_oil_rpm": 2900,
    "weight_g": 9280,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-432314U denotes the heavy-duty 432-family TDO double-row series — a 70 mm bore double-row tapered unit rated 590 kN basic dynamic and 805 kN static. Unlike a pair of single-row bearings, the TDO unit of 4T-432314U integrates both rows in one article: the 116 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Speed planning uses both catalogue columns: grease 2,200 r/min is the mechanical ceiling, oil 2,900 r/min with oil lubrication — a 700 r/min margin at this size. TDO construction means the two cone assemblies of 4T-432314U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 70 mm shaft. Induction heating to max 120 °C is the standard fitting method at this 70 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 70 mm unit by induction heating (max 120 °C); at 9.28 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432314U its 116 mm width and 590 kN rating at the 70 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 95.5 kN Cu.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-432314U feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The internal clearance of 4T-432314U is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "At inspection do not mix the cone assemblies of 4T-432314U with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 590/805 kN ratings and 95.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432314U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432314U?",
        "a": "4T-432314U is a double-row tapered roller bearing of TDO (back-to-back) construction: 70 mm bore, 150 mm outside diameter and 116 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 590 kN, C0 805 kN, Cu 95.5 kN, grease limiting speed 2,200 r/min, oil speed 2,900 r/min, mass about 9.28 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 70 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432314U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432314U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 116 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432314U mean?",
        "a": "Suffix reading on 432314U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432314U list two speeds, 2,200 and 2,900 r/min?",
        "a": "The lower figure, 2,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432314U at 2,900 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432314U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=194",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432314u",
      "4t-432314u",
      "432314U",
      "4T-432314U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430215",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430215",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 75,
    "D_mm": 130,
    "B_mm": 62,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 264,
    "static_load_kN": 350,
    "limiting_speed_rpm": 2300,
    "max_rpm": 2300,
    "speed_oil_rpm": 3000,
    "weight_g": 3100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430215 is the NTN 4T catalogue entry for a 75×130×62 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Unlike a pair of single-row bearings, the TDO unit of 4T-430215 integrates both rows in one article: the 62 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. 2203E prints no Cu fatigue load limit for 4T-430215 (the dash in the Cu column); life work for this size uses the 264/350 kN C/C0 pair directly. The internal clearance of 4T-430215 is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 62 mm overall width is the finished dimension. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-430215; the double cup must seat square across its full 62 mm width.",
    "applications": [
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "Mount the 75 mm unit by induction heating (max 120 °C); at 3.1 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430215 narrower and faster than the 432 heavy execution of the same 75 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-430215 feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Grease packs must leave free volume across the 62 mm width; over-greasing a unit churning near the 3,000 r/min oil-band speed raises temperature and expels the grease.",
      "Grease packs must leave free volume across the 62 mm width; over-greasing a unit churning near the 3,000 r/min oil-band speed raises temperature and expels the grease.",
      "The 264/350 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430215; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430215?",
        "a": "4T-430215 is a double-row tapered roller bearing of TDO (back-to-back) construction: 75 mm bore, 130 mm outside diameter and 62 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 264 kN, C0 350 kN (2203E prints a dash for Cu on this size), grease limiting speed 2,300 r/min, oil speed 3,000 r/min, mass about 3.1 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 75 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430215 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430215 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 62 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430215 mean?",
        "a": "With no letter suffix, 430215 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-430215 list two speeds, 2,300 and 3,000 r/min?",
        "a": "The lower figure, 2,300 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430215 at 3,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430215",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-430215",
      "430215",
      "4T-430215"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432215U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432215U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 75,
    "D_mm": 130,
    "B_mm": 74,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 320,
    "static_load_kN": 445,
    "fatigue_load_limit_kN": 54,
    "limiting_speed_rpm": 2300,
    "max_rpm": 2300,
    "speed_oil_rpm": 3000,
    "weight_g": 3680,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-432215U belongs to the heavy-duty 432-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Reading the designation: the last two digits 15 are the bore code, ×5 = 75 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. The fatigue load limit Cu printed for 4T-432215U is 54 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-432215U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 75 mm shaft. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 75 mm size before ordering 4T-432215U.",
    "applications": [
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 75 mm unit by induction heating (max 120 °C); at 3.68 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432215U its 74 mm width and 320 kN rating at the 75 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 54 kN Cu.",
      "The internal clearance of 4T-432215U is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Order by the full 432215U code including suffixes — U, X, DX, E1 and UTG variants share the 75 mm bore but are different articles with different internal geometry.",
      "At inspection do not mix the cone assemblies of 4T-432215U with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 320/445 kN ratings and 54 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432215U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432215U?",
        "a": "4T-432215U is a double-row tapered roller bearing of TDO (back-to-back) construction: 75 mm bore, 130 mm outside diameter and 74 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 320 kN, C0 445 kN, Cu 54 kN, grease limiting speed 2,300 r/min, oil speed 3,000 r/min, mass about 3.68 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 75 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432215U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432215U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 74 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432215U mean?",
        "a": "Suffix reading on 432215U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432215U list two speeds, 2,300 and 3,000 r/min?",
        "a": "The lower figure, 2,300 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432215U at 3,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432215U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432215u",
      "4t-432215u",
      "432215U",
      "4T-432215U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430315DU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430315DU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 75,
    "D_mm": 160,
    "B_mm": 87,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 410,
    "static_load_kN": 510,
    "fatigue_load_limit_kN": 59.5,
    "limiting_speed_rpm": 1700,
    "max_rpm": 1700,
    "speed_oil_rpm": 2300,
    "weight_g": 7310,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-430315DU denotes the light-duty 430-family TDO double-row series — a 75 mm bore double-row tapered unit rated 410 kN basic dynamic and 510 kN static. Unlike a pair of single-row bearings, the TDO unit of 4T-430315DU integrates both rows in one article: the 87 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The 42.5 mm radial section over the 75 mm bore carries two roller rows across the 87 mm width; abutment shoulders must clear both cone bores and the double-cup OD. The internal clearance of 4T-430315DU is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 87 mm overall width is the finished dimension. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-430315DU; the double cup must seat square across its full 87 mm width.",
    "applications": [
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "Mount the 75 mm unit by induction heating (max 120 °C); at 7.31 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430315DU narrower and faster than the 432 heavy execution of the same 75 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 42.5 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-430315DU or the cones bottom out on the radius.",
      "An unloaded 4T-430315DU near 1,700 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "At inspection do not mix the cone assemblies of 4T-430315DU with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 410/510 kN ratings and 59.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430315DU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430315DU?",
        "a": "4T-430315DU is a double-row tapered roller bearing of TDO (back-to-back) construction: 75 mm bore, 160 mm outside diameter and 87 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 410 kN, C0 510 kN, Cu 59.5 kN, grease limiting speed 1,700 r/min, oil speed 2,300 r/min, mass about 7.31 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 75 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430315DU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430315DU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 87 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430315DU mean?",
        "a": "Suffix reading on 430315DU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; D is an internal-design revision letter of the base number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430315DU list two speeds, 1,700 and 2,300 r/min?",
        "a": "The lower figure, 1,700 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430315DU at 2,300 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430315DU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430315du",
      "4t-430315du",
      "430315DU",
      "4T-430315DU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430315XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430315XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 75,
    "D_mm": 160,
    "B_mm": 87,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 485,
    "static_load_kN": 605,
    "fatigue_load_limit_kN": 70,
    "limiting_speed_rpm": 2000,
    "max_rpm": 2000,
    "speed_oil_rpm": 2700,
    "weight_g": 7710,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 75 mm shaft needing a compact two-direction thrust location, NTN lists 4T-430315XU, a TDO double-row 4T unit of 485 kN C and 605 kN C0 in the light-duty 430-family TDO double-row series. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 75 mm bore the 432 execution carries a wider, heavier section than the 430. Speed planning uses both catalogue columns: grease 2,000 r/min is the mechanical ceiling, oil 2,700 r/min with oil lubrication — a 700 r/min margin at this size. Because the unit is preset, mounting 4T-430315XU resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 75 mm size before ordering 4T-430315XU.",
    "applications": [
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "Mount the 75 mm unit by induction heating (max 120 °C); at 7.71 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430315XU narrower and faster than the 432 heavy execution of the same 75 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-430315XU near 2,000 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Order by the full 430315XU code including suffixes — U, X, DX, E1 and UTG variants share the 75 mm bore but are different articles with different internal geometry.",
      "At inspection do not mix the cone assemblies of 4T-430315XU with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 485/605 kN ratings and 70 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430315XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430315XU?",
        "a": "4T-430315XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 75 mm bore, 160 mm outside diameter and 87 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 485 kN, C0 605 kN, Cu 70 kN, grease limiting speed 2,000 r/min, oil speed 2,700 r/min, mass about 7.71 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 75 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430315XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430315XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 87 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430315XU mean?",
        "a": "Suffix reading on 430315XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430315XU list two speeds, 2,000 and 2,700 r/min?",
        "a": "The lower figure, 2,000 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430315XU at 2,700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430315XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430315xu",
      "4t-430315xu",
      "430315XU",
      "4T-430315XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432315U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432315U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 75,
    "D_mm": 160,
    "B_mm": 125,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 675,
    "static_load_kN": 935,
    "fatigue_load_limit_kN": 109,
    "limiting_speed_rpm": 2000,
    "max_rpm": 2000,
    "speed_oil_rpm": 2700,
    "weight_g": 11500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-432315U at 75 mm bore, 160 mm OD and 125 mm overall width, with a grease limiting speed of 2,000 r/min and an oil ceiling of 2,700 r/min. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 432315U reads accordingly. The 42.5 mm radial section over the 75 mm bore carries two roller rows across the 125 mm width; abutment shoulders must clear both cone bores and the double-cup OD. TDO construction means the two cone assemblies of 4T-432315U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 75 mm shaft. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-432315U; the double cup must seat square across its full 125 mm width.",
    "applications": [
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 75 mm unit by induction heating (max 120 °C); at 11.5 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432315U its 125 mm width and 675 kN rating at the 75 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 109 kN Cu.",
      "Order by the full 432315U code including suffixes — U, X, DX, E1 and UTG variants share the 75 mm bore but are different articles with different internal geometry.",
      "Grease packs must leave free volume across the 125 mm width; over-greasing a unit churning near the 2,700 r/min oil-band speed raises temperature and expels the grease.",
      "Grease packs must leave free volume across the 125 mm width; over-greasing a unit churning near the 2,700 r/min oil-band speed raises temperature and expels the grease.",
      "The 675/935 kN ratings and 109 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432315U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432315U?",
        "a": "4T-432315U is a double-row tapered roller bearing of TDO (back-to-back) construction: 75 mm bore, 160 mm outside diameter and 125 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 675 kN, C0 935 kN, Cu 109 kN, grease limiting speed 2,000 r/min, oil speed 2,700 r/min, mass about 11.5 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 75 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432315U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432315U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 125 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432315U mean?",
        "a": "Suffix reading on 432315U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432315U list two speeds, 2,000 and 2,700 r/min?",
        "a": "The lower figure, 2,000 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432315U at 2,700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432315U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432315u",
      "4t-432315u",
      "432315U",
      "4T-432315U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430216XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430216XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 80,
    "D_mm": 140,
    "B_mm": 64,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 305,
    "static_load_kN": 400,
    "fatigue_load_limit_kN": 47.5,
    "limiting_speed_rpm": 2100,
    "max_rpm": 2100,
    "speed_oil_rpm": 2800,
    "weight_g": 3760,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430216XU belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Unlike a pair of single-row bearings, the TDO unit of 4T-430216XU integrates both rows in one article: the 64 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Grease relubrication at the 2,100 r/min limiting speed must reach both roller rows; sustaining 2,800 r/min needs an oil supply with defined flow through the double cup. TDO construction means the two cone assemblies of 4T-430216XU face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 80 mm shaft. Mount 4T-430216XU as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "Mount the 80 mm unit by induction heating (max 120 °C); at 3.76 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430216XU narrower and faster than the 432 heavy execution of the same 80 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Open 4T-430216XU units have no seals: the housing must seal both rows or the 2,100 r/min grease figure is meaningless once contamination enters.",
      "The 305 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Grease packs must leave free volume across the 64 mm width; over-greasing a unit churning near the 2,800 r/min oil-band speed raises temperature and expels the grease.",
      "The 305/400 kN ratings and 47.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430216XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430216XU?",
        "a": "4T-430216XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 80 mm bore, 140 mm outside diameter and 64 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 305 kN, C0 400 kN, Cu 47.5 kN, grease limiting speed 2,100 r/min, oil speed 2,800 r/min, mass about 3.76 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 80 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430216XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430216XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 64 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430216XU mean?",
        "a": "Suffix reading on 430216XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430216XU list two speeds, 2,100 and 2,800 r/min?",
        "a": "The lower figure, 2,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430216XU at 2,800 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430216XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430216xu",
      "4t-430216xu",
      "430216XU",
      "4T-430216XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432216XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432216XU",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 80,
    "D_mm": 140,
    "B_mm": 78,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 380,
    "static_load_kN": 530,
    "fatigue_load_limit_kN": 63,
    "limiting_speed_rpm": 2100,
    "max_rpm": 2100,
    "speed_oil_rpm": 2800,
    "weight_g": 4700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-432216XU belongs to the heavy-duty 432-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Unlike a pair of single-row bearings, the TDO unit of 4T-432216XU integrates both rows in one article: the 78 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Double-row capacity is not twice a single-row bearing: the printed 380 kN C already accounts for load sharing between the two rows of 4T-432216XU, so apply it directly in the L10 calculation. The internal clearance of 4T-432216XU is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 78 mm overall width is the finished dimension. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-432216XU; the double cup must seat square across its full 78 mm width.",
    "applications": [
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "Mount the 80 mm unit by induction heating (max 120 °C); at 4.7 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432216XU its 78 mm width and 380 kN rating at the 80 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 63 kN Cu.",
      "Grease packs must leave free volume across the 78 mm width; over-greasing a unit churning near the 2,800 r/min oil-band speed raises temperature and expels the grease.",
      "Open 4T-432216XU units have no seals: the housing must seal both rows or the 2,100 r/min grease figure is meaningless once contamination enters.",
      "The internal clearance of 4T-432216XU is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 380/530 kN ratings and 63 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432216XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432216XU?",
        "a": "4T-432216XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 80 mm bore, 140 mm outside diameter and 78 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 380 kN, C0 530 kN, Cu 63 kN, grease limiting speed 2,100 r/min, oil speed 2,800 r/min, mass about 4.7 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 80 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432216XU belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432216XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 78 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432216XU mean?",
        "a": "Suffix reading on 432216XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432216XU list two speeds, 2,100 and 2,800 r/min?",
        "a": "The lower figure, 2,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432216XU at 2,800 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432216XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432216xu",
      "4t-432216xu",
      "432216XU",
      "4T-432216XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430316DU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430316DU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 80,
    "D_mm": 170,
    "B_mm": 92,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 450,
    "static_load_kN": 565,
    "fatigue_load_limit_kN": 64.5,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 2200,
    "weight_g": 8990,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430316DU is the NTN 4T catalogue entry for a 80×170×92 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 430316DU reads accordingly. Catalogue mass of 4T-430316DU is 8.99 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. Because the unit is preset, mounting 4T-430316DU resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. With a rotating shaft a k5/m5 seat on the 80 mm journal and a located cup in the housing are typical practice for 4T-430316DU.",
    "applications": [
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "Mount the 80 mm unit by induction heating (max 120 °C); at 8.99 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430316DU narrower and faster than the 432 heavy execution of the same 80 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 92 mm width, load spread and clearance logic of 4T-430316DU are unit-specific.",
      "The internal clearance of 4T-430316DU is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Order by the full 430316DU code including suffixes — U, X, DX, E1 and UTG variants share the 80 mm bore but are different articles with different internal geometry.",
      "The 450/565 kN ratings and 64.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430316DU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430316DU?",
        "a": "4T-430316DU is a double-row tapered roller bearing of TDO (back-to-back) construction: 80 mm bore, 170 mm outside diameter and 92 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 450 kN, C0 565 kN, Cu 64.5 kN, grease limiting speed 1,600 r/min, oil speed 2,200 r/min, mass about 8.99 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 80 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430316DU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430316DU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 92 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430316DU mean?",
        "a": "Suffix reading on 430316DU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; D is an internal-design revision letter of the base number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430316DU list two speeds, 1,600 and 2,200 r/min?",
        "a": "The lower figure, 1,600 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430316DU at 2,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430316DU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430316du",
      "4t-430316du",
      "430316DU",
      "4T-430316DU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430316XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430316XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 80,
    "D_mm": 170,
    "B_mm": 92,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 555,
    "static_load_kN": 700,
    "fatigue_load_limit_kN": 79.5,
    "limiting_speed_rpm": 1900,
    "max_rpm": 1900,
    "speed_oil_rpm": 2500,
    "weight_g": 9400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430316XU is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 80×170×92 mm. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 430316XU reads accordingly. Double-row capacity is not twice a single-row bearing: the printed 555 kN C already accounts for load sharing between the two rows of 4T-430316XU, so apply it directly in the L10 calculation. Because the unit is preset, mounting 4T-430316XU resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. The open unit carries no seals; the housing of 4T-430316XU must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "Mount the 80 mm unit by induction heating (max 120 °C); at 9.4 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430316XU narrower and faster than the 432 heavy execution of the same 80 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 45.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-430316XU or the cones bottom out on the radius.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 92 mm width, load spread and clearance logic of 4T-430316XU are unit-specific.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 170 mm OD clamping uniformly around the circumference.",
      "The 555/700 kN ratings and 79.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430316XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430316XU?",
        "a": "4T-430316XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 80 mm bore, 170 mm outside diameter and 92 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 555 kN, C0 700 kN, Cu 79.5 kN, grease limiting speed 1,900 r/min, oil speed 2,500 r/min, mass about 9.4 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 80 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430316XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430316XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 92 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430316XU mean?",
        "a": "Suffix reading on 430316XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430316XU list two speeds, 1,900 and 2,500 r/min?",
        "a": "The lower figure, 1,900 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430316XU at 2,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430316XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430316xu",
      "4t-430316xu",
      "430316XU",
      "4T-430316XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432316U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432316U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 80,
    "D_mm": 170,
    "B_mm": 131,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 755,
    "static_load_kN": 1050,
    "fatigue_load_limit_kN": 120,
    "limiting_speed_rpm": 1900,
    "max_rpm": 1900,
    "speed_oil_rpm": 2500,
    "weight_g": 13600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-432316U is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 80×170×131 mm. Reading the designation: the last two digits 16 are the bore code, ×5 = 80 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. Catalogue mass of 4T-432316U is 13.6 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. TDO construction means the two cone assemblies of 4T-432316U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 80 mm shaft. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-432316U.",
    "applications": [
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 80 mm unit by induction heating (max 120 °C); at 13.6 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432316U its 131 mm width and 755 kN rating at the 80 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 120 kN Cu.",
      "An unloaded 4T-432316U near 1,900 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "An unloaded 4T-432316U near 1,900 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 131 mm width, load spread and clearance logic of 4T-432316U are unit-specific.",
      "The 755/1050 kN ratings and 120 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432316U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432316U?",
        "a": "4T-432316U is a double-row tapered roller bearing of TDO (back-to-back) construction: 80 mm bore, 170 mm outside diameter and 131 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 755 kN, C0 1050 kN, Cu 120 kN, grease limiting speed 1,900 r/min, oil speed 2,500 r/min, mass about 13.6 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 80 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432316U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432316U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 131 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432316U mean?",
        "a": "Suffix reading on 432316U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432316U list two speeds, 1,900 and 2,500 r/min?",
        "a": "The lower figure, 1,900 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432316U at 2,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432316U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432316u",
      "4t-432316u",
      "432316U",
      "4T-432316U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430217XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430217XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 85,
    "D_mm": 150,
    "B_mm": 70,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 345,
    "static_load_kN": 465,
    "fatigue_load_limit_kN": 54,
    "limiting_speed_rpm": 2000,
    "max_rpm": 2000,
    "speed_oil_rpm": 2700,
    "weight_g": 4760,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430217XU is the NTN 4T catalogue entry for a 85×150×70 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Reading the designation: the last two digits 17 are the bore code, ×5 = 85 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. The fatigue load limit Cu printed for 4T-430217XU is 54 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. Because the unit is preset, mounting 4T-430217XU resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. At 345 kN C the unit offers about 4.1 kN per millimetre of the 85 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 2,700 r/min.",
    "applications": [
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "Mount the 85 mm unit by induction heating (max 120 °C); at 4.76 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430217XU narrower and faster than the 432 heavy execution of the same 85 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 70 mm width, load spread and clearance logic of 4T-430217XU are unit-specific.",
      "At inspection do not mix the cone assemblies of 4T-430217XU with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 32.5 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-430217XU or the cones bottom out on the radius.",
      "The 345/465 kN ratings and 54 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430217XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430217XU?",
        "a": "4T-430217XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 85 mm bore, 150 mm outside diameter and 70 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 345 kN, C0 465 kN, Cu 54 kN, grease limiting speed 2,000 r/min, oil speed 2,700 r/min, mass about 4.76 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 85 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430217XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430217XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 70 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430217XU mean?",
        "a": "Suffix reading on 430217XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430217XU list two speeds, 2,000 and 2,700 r/min?",
        "a": "The lower figure, 2,000 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430217XU at 2,700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430217XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430217xu",
      "4t-430217xu",
      "430217XU",
      "4T-430217XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432217XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432217XU",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 85,
    "D_mm": 150,
    "B_mm": 86,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 425,
    "static_load_kN": 600,
    "fatigue_load_limit_kN": 70,
    "limiting_speed_rpm": 2000,
    "max_rpm": 2000,
    "speed_oil_rpm": 2700,
    "weight_g": 5990,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-432217XU denotes the heavy-duty 432-family TDO double-row series — a 85 mm bore double-row tapered unit rated 425 kN basic dynamic and 600 kN static. Reading the designation: the last two digits 17 are the bore code, ×5 = 85 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. Selection: C 425 kN against C0 600 kN gives a C0/C ratio of 1.41; the two rows of 4T-432217XU share the combined load as one bearing position. Because the unit is preset, mounting 4T-432217XU resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. With a rotating shaft a k5/m5 seat on the 85 mm journal and a located cup in the housing are typical practice for 4T-432217XU.",
    "applications": [
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "Mount the 85 mm unit by induction heating (max 120 °C); at 5.99 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432217XU its 86 mm width and 425 kN rating at the 85 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 70 kN Cu.",
      "An unloaded 4T-432217XU near 2,000 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 425 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 425 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 425/600 kN ratings and 70 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432217XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432217XU?",
        "a": "4T-432217XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 85 mm bore, 150 mm outside diameter and 86 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 425 kN, C0 600 kN, Cu 70 kN, grease limiting speed 2,000 r/min, oil speed 2,700 r/min, mass about 5.99 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 85 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432217XU belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432217XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 86 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432217XU mean?",
        "a": "Suffix reading on 432217XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432217XU list two speeds, 2,000 and 2,700 r/min?",
        "a": "The lower figure, 2,000 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432217XU at 2,700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432217XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432217xu",
      "4t-432217xu",
      "432217XU",
      "4T-432217XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430317DU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430317DU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 85,
    "D_mm": 180,
    "B_mm": 98,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 470,
    "static_load_kN": 585,
    "fatigue_load_limit_kN": 66,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 2100,
    "weight_g": 10400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 85 mm shaft needing a compact two-direction thrust location, NTN lists 4T-430317DU, a TDO double-row 4T unit of 470 kN C and 585 kN C0 in the light-duty 430-family TDO double-row series. Suffix reading on 430317DU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; D is an internal-design revision letter of the base number; suffixed variants are separate order numbers and are not interchangeable articles. Axial capacity is bidirectional because the rows are opposed: 4T-430317DU locates the shaft in both directions with C0 585 kN behind the static check of the more heavily loaded row. Because the unit is preset, mounting 4T-430317DU resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-430317DU.",
    "applications": [
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "Mount the 85 mm unit by induction heating (max 120 °C); at 10.4 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430317DU narrower and faster than the 432 heavy execution of the same 85 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Order by the full 430317DU code including suffixes — U, X, DX, E1 and UTG variants share the 85 mm bore but are different articles with different internal geometry.",
      "Order by the full 430317DU code including suffixes — U, X, DX, E1 and UTG variants share the 85 mm bore but are different articles with different internal geometry.",
      "The internal clearance of 4T-430317DU is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 470/585 kN ratings and 66 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430317DU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430317DU?",
        "a": "4T-430317DU is a double-row tapered roller bearing of TDO (back-to-back) construction: 85 mm bore, 180 mm outside diameter and 98 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 470 kN, C0 585 kN, Cu 66 kN, grease limiting speed 1,500 r/min, oil speed 2,100 r/min, mass about 10.4 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 85 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430317DU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430317DU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 98 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430317DU mean?",
        "a": "Suffix reading on 430317DU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; D is an internal-design revision letter of the base number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430317DU list two speeds, 1,500 and 2,100 r/min?",
        "a": "The lower figure, 1,500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430317DU at 2,100 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430317DU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430317du",
      "4t-430317du",
      "430317DU",
      "4T-430317DU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430317XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430317XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 85,
    "D_mm": 180,
    "B_mm": 98,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 580,
    "static_load_kN": 725,
    "fatigue_load_limit_kN": 81,
    "limiting_speed_rpm": 1800,
    "max_rpm": 1800,
    "speed_oil_rpm": 2400,
    "weight_g": 10800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 85 mm shaft position as 4T-430317XU: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 98 mm. Suffix reading on 430317XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles. Selection: C 580 kN against C0 725 kN gives a C0/C ratio of 1.25; the two rows of 4T-430317XU share the combined load as one bearing position. TDO construction means the two cone assemblies of 4T-430317XU face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 85 mm shaft. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-430317XU are ground as a unit.",
    "applications": [
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 85 mm unit by induction heating (max 120 °C); at 10.8 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430317XU narrower and faster than the 432 heavy execution of the same 85 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "At inspection do not mix the cone assemblies of 4T-430317XU with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-430317XU feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The internal clearance of 4T-430317XU is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 580/725 kN ratings and 81 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430317XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430317XU?",
        "a": "4T-430317XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 85 mm bore, 180 mm outside diameter and 98 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 580 kN, C0 725 kN, Cu 81 kN, grease limiting speed 1,800 r/min, oil speed 2,400 r/min, mass about 10.8 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 85 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430317XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430317XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 98 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430317XU mean?",
        "a": "Suffix reading on 430317XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430317XU list two speeds, 1,800 and 2,400 r/min?",
        "a": "The lower figure, 1,800 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430317XU at 2,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430317XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430317xu",
      "4t-430317xu",
      "430317XU",
      "4T-430317XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432317U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432317U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 85,
    "D_mm": 180,
    "B_mm": 137,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 765,
    "static_load_kN": 1050,
    "fatigue_load_limit_kN": 118,
    "limiting_speed_rpm": 1800,
    "max_rpm": 1800,
    "speed_oil_rpm": 2400,
    "weight_g": 15400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-432317U is the NTN 4T catalogue entry for a 85×180×137 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Suffix reading on 432317U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles. The 9.0 kN of dynamic capacity per millimetre of bore summarises the 765 kN rating over the 85 mm bore — compare substitution candidates on this ratio and on the 137 mm width. TDO construction means the two cone assemblies of 4T-432317U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 85 mm shaft. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-432317U's locating position.",
    "applications": [
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 85 mm unit by induction heating (max 120 °C); at 15.4 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432317U its 137 mm width and 765 kN rating at the 85 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 118 kN Cu.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 180 mm OD clamping uniformly around the circumference.",
      "The 47.5 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-432317U or the cones bottom out on the radius.",
      "The 765 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 765/1050 kN ratings and 118 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432317U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432317U?",
        "a": "4T-432317U is a double-row tapered roller bearing of TDO (back-to-back) construction: 85 mm bore, 180 mm outside diameter and 137 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 765 kN, C0 1050 kN, Cu 118 kN, grease limiting speed 1,800 r/min, oil speed 2,400 r/min, mass about 15.4 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 85 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432317U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432317U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 137 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432317U mean?",
        "a": "Suffix reading on 432317U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432317U list two speeds, 1,800 and 2,400 r/min?",
        "a": "The lower figure, 1,800 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432317U at 2,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432317U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432317u",
      "4t-432317u",
      "432317U",
      "4T-432317U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430218U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430218U",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 90,
    "D_mm": 160,
    "B_mm": 74,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 395,
    "static_load_kN": 535,
    "fatigue_load_limit_kN": 61,
    "limiting_speed_rpm": 1900,
    "max_rpm": 1900,
    "speed_oil_rpm": 2500,
    "weight_g": 5850,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-430218U denotes the light-duty 430-family TDO double-row series — a 90 mm bore double-row tapered unit rated 395 kN basic dynamic and 535 kN static. Reading the designation: the last two digits 18 are the bore code, ×5 = 90 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. Catalogue mass of 4T-430218U is 5.85 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. TDO construction means the two cone assemblies of 4T-430218U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 90 mm shaft. Axial clamping of the double cup must be uniform around the 160 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "Mount the 90 mm unit by induction heating (max 120 °C); at 5.85 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430218U narrower and faster than the 432 heavy execution of the same 90 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-430218U near 1,900 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-430218U feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 160 mm OD clamping uniformly around the circumference.",
      "The 395/535 kN ratings and 61 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430218U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430218U?",
        "a": "4T-430218U is a double-row tapered roller bearing of TDO (back-to-back) construction: 90 mm bore, 160 mm outside diameter and 74 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 395 kN, C0 535 kN, Cu 61 kN, grease limiting speed 1,900 r/min, oil speed 2,500 r/min, mass about 5.85 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 90 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430218U belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430218U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 74 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430218U mean?",
        "a": "Suffix reading on 430218U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430218U list two speeds, 1,900 and 2,500 r/min?",
        "a": "The lower figure, 1,900 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430218U at 2,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430218U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430218u",
      "4t-430218u",
      "430218U",
      "4T-430218U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432218U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432218U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 90,
    "D_mm": 160,
    "B_mm": 94,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 500,
    "static_load_kN": 720,
    "fatigue_load_limit_kN": 82.5,
    "limiting_speed_rpm": 1900,
    "max_rpm": 1900,
    "speed_oil_rpm": 2500,
    "weight_g": 7350,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-432218U denotes the heavy-duty 432-family TDO double-row series — a 90 mm bore double-row tapered unit rated 500 kN basic dynamic and 720 kN static. Unlike a pair of single-row bearings, the TDO unit of 4T-432218U integrates both rows in one article: the 94 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Catalogue mass of 4T-432218U is 7.35 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. TDO construction means the two cone assemblies of 4T-432218U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 90 mm shaft. The open unit carries no seals; the housing of 4T-432218U must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 90 mm unit by induction heating (max 120 °C); at 7.35 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432218U its 94 mm width and 500 kN rating at the 90 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 82.5 kN Cu.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 94 mm width, load spread and clearance logic of 4T-432218U are unit-specific.",
      "An unloaded 4T-432218U near 1,900 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 500 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 500/720 kN ratings and 82.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432218U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432218U?",
        "a": "4T-432218U is a double-row tapered roller bearing of TDO (back-to-back) construction: 90 mm bore, 160 mm outside diameter and 94 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 500 kN, C0 720 kN, Cu 82.5 kN, grease limiting speed 1,900 r/min, oil speed 2,500 r/min, mass about 7.35 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 90 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432218U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432218U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 94 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432218U mean?",
        "a": "Suffix reading on 432218U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432218U list two speeds, 1,900 and 2,500 r/min?",
        "a": "The lower figure, 1,900 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432218U at 2,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432218U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432218u",
      "4t-432218u",
      "432218U",
      "4T-432218U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430318DU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430318DU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 90,
    "D_mm": 190,
    "B_mm": 102,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 515,
    "static_load_kN": 645,
    "fatigue_load_limit_kN": 71,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 1900,
    "weight_g": 12200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430318DU is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 90×190×102 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-430318DU integrates both rows in one article: the 102 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Speed planning uses both catalogue columns: grease 1,500 r/min is the mechanical ceiling, oil 1,900 r/min with oil lubrication — a 400 r/min margin at this size. TDO construction means the two cone assemblies of 4T-430318DU face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 90 mm shaft. Induction heating to max 120 °C is the standard fitting method at this 90 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 90 mm unit by induction heating (max 120 °C); at 12.2 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430318DU narrower and faster than the 432 heavy execution of the same 90 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The internal clearance of 4T-430318DU is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Open 4T-430318DU units have no seals: the housing must seal both rows or the 1,500 r/min grease figure is meaningless once contamination enters.",
      "The 515 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 515/645 kN ratings and 71 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430318DU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430318DU?",
        "a": "4T-430318DU is a double-row tapered roller bearing of TDO (back-to-back) construction: 90 mm bore, 190 mm outside diameter and 102 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 515 kN, C0 645 kN, Cu 71 kN, grease limiting speed 1,500 r/min, oil speed 1,900 r/min, mass about 12.2 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 90 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430318DU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430318DU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 102 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430318DU mean?",
        "a": "Suffix reading on 430318DU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; D is an internal-design revision letter of the base number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430318DU list two speeds, 1,500 and 1,900 r/min?",
        "a": "The lower figure, 1,500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430318DU at 1,900 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430318DU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430318du",
      "4t-430318du",
      "430318DU",
      "4T-430318DU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430318U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430318U",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 90,
    "D_mm": 190,
    "B_mm": 102,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 640,
    "static_load_kN": 815,
    "fatigue_load_limit_kN": 89,
    "limiting_speed_rpm": 1700,
    "max_rpm": 1700,
    "speed_oil_rpm": 2300,
    "weight_g": 12500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430318U belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 430318U reads accordingly. Double-row capacity is not twice a single-row bearing: the printed 640 kN C already accounts for load sharing between the two rows of 4T-430318U, so apply it directly in the L10 calculation. TDO construction means the two cone assemblies of 4T-430318U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 90 mm shaft. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-430318U's locating position.",
    "applications": [
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "Mount the 90 mm unit by induction heating (max 120 °C); at 12.5 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430318U narrower and faster than the 432 heavy execution of the same 90 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Grease packs must leave free volume across the 102 mm width; over-greasing a unit churning near the 2,300 r/min oil-band speed raises temperature and expels the grease.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 102 mm width, load spread and clearance logic of 4T-430318U are unit-specific.",
      "An unloaded 4T-430318U near 1,700 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 640/815 kN ratings and 89 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430318U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430318U?",
        "a": "4T-430318U is a double-row tapered roller bearing of TDO (back-to-back) construction: 90 mm bore, 190 mm outside diameter and 102 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 640 kN, C0 815 kN, Cu 89 kN, grease limiting speed 1,700 r/min, oil speed 2,300 r/min, mass about 12.5 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 90 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430318U belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430318U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 102 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430318U mean?",
        "a": "Suffix reading on 430318U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430318U list two speeds, 1,700 and 2,300 r/min?",
        "a": "The lower figure, 1,700 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430318U at 2,300 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430318U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430318u",
      "4t-430318u",
      "430318U",
      "4T-430318U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432318U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432318U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 90,
    "D_mm": 190,
    "B_mm": 144,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 855,
    "static_load_kN": 1190,
    "fatigue_load_limit_kN": 131,
    "limiting_speed_rpm": 1700,
    "max_rpm": 1700,
    "speed_oil_rpm": 2300,
    "weight_g": 18300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-432318U belongs to the heavy-duty 432-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 90 mm bore the 432 execution carries a wider, heavier section than the 430. Double-row capacity is not twice a single-row bearing: the printed 855 kN C already accounts for load sharing between the two rows of 4T-432318U, so apply it directly in the L10 calculation. TDO construction means the two cone assemblies of 4T-432318U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 90 mm shaft. At 855 kN C the unit offers about 9.5 kN per millimetre of the 90 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 2,300 r/min.",
    "applications": [
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 90 mm unit by induction heating (max 120 °C); at 18.3 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432318U its 144 mm width and 855 kN rating at the 90 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 131 kN Cu.",
      "Open 4T-432318U units have no seals: the housing must seal both rows or the 1,700 r/min grease figure is meaningless once contamination enters.",
      "At inspection do not mix the cone assemblies of 4T-432318U with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 50.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-432318U or the cones bottom out on the radius.",
      "The 855/1190 kN ratings and 131 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432318U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432318U?",
        "a": "4T-432318U is a double-row tapered roller bearing of TDO (back-to-back) construction: 90 mm bore, 190 mm outside diameter and 144 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 855 kN, C0 1190 kN, Cu 131 kN, grease limiting speed 1,700 r/min, oil speed 2,300 r/min, mass about 18.3 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 90 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432318U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432318U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 144 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432318U mean?",
        "a": "Suffix reading on 432318U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432318U list two speeds, 1,700 and 2,300 r/min?",
        "a": "The lower figure, 1,700 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432318U at 2,300 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432318U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432318u",
      "4t-432318u",
      "432318U",
      "4T-432318U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430219XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430219XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 95,
    "D_mm": 170,
    "B_mm": 78,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 430,
    "static_load_kN": 580,
    "fatigue_load_limit_kN": 65,
    "limiting_speed_rpm": 1800,
    "max_rpm": 1800,
    "speed_oil_rpm": 2400,
    "weight_g": 6850,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430219XU is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 95×170×78 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-430219XU integrates both rows in one article: the 78 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Grease relubrication at the 1,800 r/min limiting speed must reach both roller rows; sustaining 2,400 r/min needs an oil supply with defined flow through the double cup. Because the unit is preset, mounting 4T-430219XU resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. With a rotating shaft a k5/m5 seat on the 95 mm journal and a located cup in the housing are typical practice for 4T-430219XU.",
    "applications": [
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "Mount the 95 mm unit by induction heating (max 120 °C); at 6.85 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430219XU narrower and faster than the 432 heavy execution of the same 95 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 170 mm OD clamping uniformly around the circumference.",
      "An unloaded 4T-430219XU near 1,800 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 170 mm OD clamping uniformly around the circumference.",
      "The 430/580 kN ratings and 65 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430219XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430219XU?",
        "a": "4T-430219XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 95 mm bore, 170 mm outside diameter and 78 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 430 kN, C0 580 kN, Cu 65 kN, grease limiting speed 1,800 r/min, oil speed 2,400 r/min, mass about 6.85 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 95 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430219XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430219XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 78 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430219XU mean?",
        "a": "Suffix reading on 430219XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430219XU list two speeds, 1,800 and 2,400 r/min?",
        "a": "The lower figure, 1,800 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430219XU at 2,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430219XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430219xu",
      "4t-430219xu",
      "430219XU",
      "4T-430219XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432219XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432219XU",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 95,
    "D_mm": 170,
    "B_mm": 100,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 570,
    "static_load_kN": 835,
    "fatigue_load_limit_kN": 93.5,
    "limiting_speed_rpm": 1800,
    "max_rpm": 1800,
    "speed_oil_rpm": 2400,
    "weight_g": 9200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 95 mm shaft needing a compact two-direction thrust location, NTN lists 4T-432219XU, a TDO double-row 4T unit of 570 kN C and 835 kN C0 in the heavy-duty 432-family TDO double-row series. Unlike a pair of single-row bearings, the TDO unit of 4T-432219XU integrates both rows in one article: the 100 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The 6.0 kN of dynamic capacity per millimetre of bore summarises the 570 kN rating over the 95 mm bore — compare substitution candidates on this ratio and on the 100 mm width. TDO construction means the two cone assemblies of 4T-432219XU face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 95 mm shaft. Induction heating to max 120 °C is the standard fitting method at this 95 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 95 mm unit by induction heating (max 120 °C); at 9.2 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432219XU its 100 mm width and 570 kN rating at the 95 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 93.5 kN Cu.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 100 mm width, load spread and clearance logic of 4T-432219XU are unit-specific.",
      "The 37.5 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-432219XU or the cones bottom out on the radius.",
      "An unloaded 4T-432219XU near 1,800 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 570/835 kN ratings and 93.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432219XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432219XU?",
        "a": "4T-432219XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 95 mm bore, 170 mm outside diameter and 100 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 570 kN, C0 835 kN, Cu 93.5 kN, grease limiting speed 1,800 r/min, oil speed 2,400 r/min, mass about 9.2 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 95 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432219XU belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432219XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 100 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432219XU mean?",
        "a": "Suffix reading on 432219XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432219XU list two speeds, 1,800 and 2,400 r/min?",
        "a": "The lower figure, 1,800 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432219XU at 2,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432219XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432219xu",
      "4t-432219xu",
      "432219XU",
      "4T-432219XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430319XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430319XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 95,
    "D_mm": 200,
    "B_mm": 108,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 700,
    "static_load_kN": 890,
    "fatigue_load_limit_kN": 96.5,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 2100,
    "weight_g": 14600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430319XU belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 430319XU reads accordingly. The 7.4 kN of dynamic capacity per millimetre of bore summarises the 700 kN rating over the 95 mm bore — compare substitution candidates on this ratio and on the 108 mm width. The internal clearance of 4T-430319XU is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 108 mm overall width is the finished dimension. Axial clamping of the double cup must be uniform around the 200 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "Mount the 95 mm unit by induction heating (max 120 °C); at 14.6 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430319XU narrower and faster than the 432 heavy execution of the same 95 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The internal clearance of 4T-430319XU is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "At inspection do not mix the cone assemblies of 4T-430319XU with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-430319XU feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 700/890 kN ratings and 96.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430319XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430319XU?",
        "a": "4T-430319XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 95 mm bore, 200 mm outside diameter and 108 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 700 kN, C0 890 kN, Cu 96.5 kN, grease limiting speed 1,600 r/min, oil speed 2,100 r/min, mass about 14.6 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 95 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430319XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430319XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 108 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430319XU mean?",
        "a": "Suffix reading on 430319XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430319XU list two speeds, 1,600 and 2,100 r/min?",
        "a": "The lower figure, 1,600 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430319XU at 2,100 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430319XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430319xu",
      "4t-430319xu",
      "430319XU",
      "4T-430319XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432319U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432319U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 95,
    "D_mm": 200,
    "B_mm": 151,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 955,
    "static_load_kN": 1340,
    "fatigue_load_limit_kN": 146,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 2100,
    "weight_g": 21000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 95 mm shaft position as 4T-432319U: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 151 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-432319U integrates both rows in one article: the 151 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Grease relubrication at the 1,600 r/min limiting speed must reach both roller rows; sustaining 2,100 r/min needs an oil supply with defined flow through the double cup. TDO construction means the two cone assemblies of 4T-432319U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 95 mm shaft. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 95 mm size before ordering 4T-432319U.",
    "applications": [
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 95 mm unit by induction heating (max 120 °C); at 21 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432319U its 151 mm width and 955 kN rating at the 95 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 146 kN Cu.",
      "The internal clearance of 4T-432319U is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 200 mm OD clamping uniformly around the circumference.",
      "The internal clearance of 4T-432319U is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 955/1340 kN ratings and 146 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432319U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432319U?",
        "a": "4T-432319U is a double-row tapered roller bearing of TDO (back-to-back) construction: 95 mm bore, 200 mm outside diameter and 151 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 955 kN, C0 1340 kN, Cu 146 kN, grease limiting speed 1,600 r/min, oil speed 2,100 r/min, mass about 21 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 95 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432319U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432319U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 151 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432319U mean?",
        "a": "Suffix reading on 432319U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432319U list two speeds, 1,600 and 2,100 r/min?",
        "a": "The lower figure, 1,600 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432319U at 2,100 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432319U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432319u",
      "4t-432319u",
      "432319U",
      "4T-432319U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430220XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430220XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 100,
    "D_mm": 180,
    "B_mm": 83,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 490,
    "static_load_kN": 675,
    "fatigue_load_limit_kN": 74.5,
    "limiting_speed_rpm": 1700,
    "max_rpm": 1700,
    "speed_oil_rpm": 2200,
    "weight_g": 8270,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430220XU belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 100 mm bore the 432 execution carries a wider, heavier section than the 430. The fatigue load limit Cu printed for 4T-430220XU is 74.5 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-430220XU face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 100 mm shaft. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-430220XU.",
    "applications": [
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 100 mm unit by induction heating (max 120 °C); at 8.27 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430220XU narrower and faster than the 432 heavy execution of the same 100 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-430220XU near 1,700 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 490 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Order by the full 430220XU code including suffixes — U, X, DX, E1 and UTG variants share the 100 mm bore but are different articles with different internal geometry.",
      "The 490/675 kN ratings and 74.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430220XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430220XU?",
        "a": "4T-430220XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 100 mm bore, 180 mm outside diameter and 83 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 490 kN, C0 675 kN, Cu 74.5 kN, grease limiting speed 1,700 r/min, oil speed 2,200 r/min, mass about 8.27 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 100 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430220XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430220XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 83 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430220XU mean?",
        "a": "Suffix reading on 430220XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430220XU list two speeds, 1,700 and 2,200 r/min?",
        "a": "The lower figure, 1,700 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430220XU at 2,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430220XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430220xu",
      "4t-430220xu",
      "430220XU",
      "4T-430220XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432220XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432220XU",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 100,
    "D_mm": 180,
    "B_mm": 107,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 630,
    "static_load_kN": 925,
    "fatigue_load_limit_kN": 102,
    "limiting_speed_rpm": 1700,
    "max_rpm": 1700,
    "speed_oil_rpm": 2200,
    "weight_g": 11000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-432220XU at 100 mm bore, 180 mm OD and 107 mm overall width, with a grease limiting speed of 1,700 r/min and an oil ceiling of 2,200 r/min. Suffix reading on 432220XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles. Grease relubrication at the 1,700 r/min limiting speed must reach both roller rows; sustaining 2,200 r/min needs an oil supply with defined flow through the double cup. TDO construction means the two cone assemblies of 4T-432220XU face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 100 mm shaft. The open unit carries no seals; the housing of 4T-432220XU must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 100 mm unit by induction heating (max 120 °C); at 11 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432220XU its 107 mm width and 630 kN rating at the 100 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 102 kN Cu.",
      "The internal clearance of 4T-432220XU is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Open 4T-432220XU units have no seals: the housing must seal both rows or the 1,700 r/min grease figure is meaningless once contamination enters.",
      "An unloaded 4T-432220XU near 1,700 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 630/925 kN ratings and 102 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432220XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432220XU?",
        "a": "4T-432220XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 100 mm bore, 180 mm outside diameter and 107 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 630 kN, C0 925 kN, Cu 102 kN, grease limiting speed 1,700 r/min, oil speed 2,200 r/min, mass about 11 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 100 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432220XU belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432220XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 107 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432220XU mean?",
        "a": "Suffix reading on 432220XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432220XU list two speeds, 1,700 and 2,200 r/min?",
        "a": "The lower figure, 1,700 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432220XU at 2,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432220XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432220xu",
      "4t-432220xu",
      "432220XU",
      "4T-432220XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430320XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430320XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 100,
    "D_mm": 215,
    "B_mm": 112,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 780,
    "static_load_kN": 995,
    "fatigue_load_limit_kN": 106,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 2000,
    "weight_g": 17900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 100 mm shaft needing a compact two-direction thrust location, NTN lists 4T-430320XU, a TDO double-row 4T unit of 780 kN C and 995 kN C0 in the light-duty 430-family TDO double-row series. Unlike a pair of single-row bearings, the TDO unit of 4T-430320XU integrates both rows in one article: the 112 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Selection: C 780 kN against C0 995 kN gives a C0/C ratio of 1.28; the two rows of 4T-430320XU share the combined load as one bearing position. The internal clearance of 4T-430320XU is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 112 mm overall width is the finished dimension. At 780 kN C the unit offers about 7.8 kN per millimetre of the 100 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 2,000 r/min.",
    "applications": [
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "Mount the 100 mm unit by induction heating (max 120 °C); at 17.9 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430320XU narrower and faster than the 432 heavy execution of the same 100 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Open 4T-430320XU units have no seals: the housing must seal both rows or the 1,500 r/min grease figure is meaningless once contamination enters.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 112 mm width, load spread and clearance logic of 4T-430320XU are unit-specific.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-430320XU feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 780/995 kN ratings and 106 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430320XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430320XU?",
        "a": "4T-430320XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 100 mm bore, 215 mm outside diameter and 112 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 780 kN, C0 995 kN, Cu 106 kN, grease limiting speed 1,500 r/min, oil speed 2,000 r/min, mass about 17.9 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 100 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430320XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430320XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 112 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430320XU mean?",
        "a": "Suffix reading on 430320XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430320XU list two speeds, 1,500 and 2,000 r/min?",
        "a": "The lower figure, 1,500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430320XU at 2,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430320XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430320xu",
      "4t-430320xu",
      "430320XU",
      "4T-430320XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432320U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432320U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 100,
    "D_mm": 215,
    "B_mm": 162,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1090,
    "static_load_kN": 1540,
    "fatigue_load_limit_kN": 164,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 2000,
    "weight_g": 26800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 100 mm shaft needing a compact two-direction thrust location, NTN lists 4T-432320U, a TDO double-row 4T unit of 1090 kN C and 1540 kN C0 in the heavy-duty 432-family TDO double-row series. Reading the designation: the last two digits 20 are the bore code, ×5 = 100 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. Selection: C 1090 kN against C0 1540 kN gives a C0/C ratio of 1.41; the two rows of 4T-432320U share the combined load as one bearing position. TDO construction means the two cone assemblies of 4T-432320U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 100 mm shaft. With a rotating shaft a k5/m5 seat on the 100 mm journal and a located cup in the housing are typical practice for 4T-432320U.",
    "applications": [
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 100 mm unit by induction heating (max 120 °C); at 26.8 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432320U its 162 mm width and 1090 kN rating at the 100 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 164 kN Cu.",
      "Grease packs must leave free volume across the 162 mm width; over-greasing a unit churning near the 2,000 r/min oil-band speed raises temperature and expels the grease.",
      "The 1090 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 1090 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 1090/1540 kN ratings and 164 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432320U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432320U?",
        "a": "4T-432320U is a double-row tapered roller bearing of TDO (back-to-back) construction: 100 mm bore, 215 mm outside diameter and 162 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1090 kN, C0 1540 kN, Cu 164 kN, grease limiting speed 1,500 r/min, oil speed 2,000 r/min, mass about 26.8 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 100 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432320U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432320U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 162 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432320U mean?",
        "a": "Suffix reading on 432320U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432320U list two speeds, 1,500 and 2,000 r/min?",
        "a": "The lower figure, 1,500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432320U at 2,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432320U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432320u",
      "4t-432320u",
      "432320U",
      "4T-432320U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430221XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430221XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 105,
    "D_mm": 190,
    "B_mm": 88,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 545,
    "static_load_kN": 760,
    "fatigue_load_limit_kN": 82.5,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 2100,
    "weight_g": 9800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-430221XU denotes the light-duty 430-family TDO double-row series — a 105 mm bore double-row tapered unit rated 545 kN basic dynamic and 760 kN static. Unlike a pair of single-row bearings, the TDO unit of 4T-430221XU integrates both rows in one article: the 88 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The 42.5 mm radial section over the 105 mm bore carries two roller rows across the 88 mm width; abutment shoulders must clear both cone bores and the double-cup OD. TDO construction means the two cone assemblies of 4T-430221XU face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 105 mm shaft. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 105 mm size before ordering 4T-430221XU.",
    "applications": [
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 105 mm unit by induction heating (max 120 °C); at 9.8 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430221XU narrower and faster than the 432 heavy execution of the same 105 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Open 4T-430221XU units have no seals: the housing must seal both rows or the 1,600 r/min grease figure is meaningless once contamination enters.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 190 mm OD clamping uniformly around the circumference.",
      "The internal clearance of 4T-430221XU is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 545/760 kN ratings and 82.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430221XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430221XU?",
        "a": "4T-430221XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 105 mm bore, 190 mm outside diameter and 88 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 545 kN, C0 760 kN, Cu 82.5 kN, grease limiting speed 1,600 r/min, oil speed 2,100 r/min, mass about 9.8 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 105 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430221XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430221XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 88 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430221XU mean?",
        "a": "Suffix reading on 430221XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430221XU list two speeds, 1,600 and 2,100 r/min?",
        "a": "The lower figure, 1,600 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430221XU at 2,100 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430221XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430221xu",
      "4t-430221xu",
      "430221XU",
      "4T-430221XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432221XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432221XU",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 105,
    "D_mm": 190,
    "B_mm": 115,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 720,
    "static_load_kN": 1080,
    "fatigue_load_limit_kN": 118,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 2100,
    "weight_g": 13300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-432221XU belongs to the heavy-duty 432-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Unlike a pair of single-row bearings, the TDO unit of 4T-432221XU integrates both rows in one article: the 115 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The fatigue load limit Cu printed for 4T-432221XU is 118 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. The internal clearance of 4T-432221XU is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 115 mm overall width is the finished dimension. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-432221XU are ground as a unit.",
    "applications": [
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "Mount the 105 mm unit by induction heating (max 120 °C); at 13.3 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432221XU its 115 mm width and 720 kN rating at the 105 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 118 kN Cu.",
      "Grease packs must leave free volume across the 115 mm width; over-greasing a unit churning near the 2,100 r/min oil-band speed raises temperature and expels the grease.",
      "The 720 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Open 4T-432221XU units have no seals: the housing must seal both rows or the 1,600 r/min grease figure is meaningless once contamination enters.",
      "The 720/1080 kN ratings and 118 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432221XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432221XU?",
        "a": "4T-432221XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 105 mm bore, 190 mm outside diameter and 115 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 720 kN, C0 1080 kN, Cu 118 kN, grease limiting speed 1,600 r/min, oil speed 2,100 r/min, mass about 13.3 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 105 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432221XU belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432221XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 115 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432221XU mean?",
        "a": "Suffix reading on 432221XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432221XU list two speeds, 1,600 and 2,100 r/min?",
        "a": "The lower figure, 1,600 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432221XU at 2,100 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432221XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=195",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432221xu",
      "4t-432221xu",
      "432221XU",
      "4T-432221XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323122",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323122",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 110,
    "D_mm": 180,
    "B_mm": 56,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 330,
    "static_load_kN": 485,
    "fatigue_load_limit_kN": 53,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 2200,
    "weight_g": 5540,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323122 is the NTN 4T catalogue entry for a 110×180×56 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. With no letter suffix, 323122 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code. Catalogue mass of 4T-323122 is 5.54 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. TDO construction means the two cone assemblies of 4T-323122 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 110 mm shaft. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 110 mm size before ordering 4T-323122.",
    "applications": [
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 110 mm unit by induction heating (max 120 °C); at 5.54 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-323122 its 56 mm width and 330 kN rating at the 110 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 53 kN Cu.",
      "Grease packs must leave free volume across the 56 mm width; over-greasing a unit churning near the 2,200 r/min oil-band speed raises temperature and expels the grease.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 180 mm OD clamping uniformly around the circumference.",
      "The internal clearance of 4T-323122 is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 330/485 kN ratings and 53 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323122; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323122?",
        "a": "4T-323122 is a double-row tapered roller bearing of TDO (back-to-back) construction: 110 mm bore, 180 mm outside diameter and 56 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 330 kN, C0 485 kN, Cu 53 kN, grease limiting speed 1,600 r/min, oil speed 2,200 r/min, mass about 5.54 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 110 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323122 belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323122 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 56 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323122 mean?",
        "a": "With no letter suffix, 323122 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-323122 list two speeds, 1,600 and 2,200 r/min?",
        "a": "The lower figure, 1,600 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323122 at 2,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323122",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-323122",
      "323122",
      "4T-323122"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413122",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413122",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 110,
    "D_mm": 180,
    "B_mm": 56,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 253,
    "static_load_kN": 340,
    "fatigue_load_limit_kN": 37.5,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 2200,
    "weight_g": 4930,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 110 mm shaft position as 4T-413122: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 56 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-413122 integrates both rows in one article: the 56 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The 2.3 kN of dynamic capacity per millimetre of bore summarises the 253 kN rating over the 110 mm bore — compare substitution candidates on this ratio and on the 56 mm width. Because the unit is preset, mounting 4T-413122 resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 110 mm size before ordering 4T-413122.",
    "applications": [
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "Mount the 110 mm unit by induction heating (max 120 °C); at 4.93 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-413122 narrower and faster than the 432 heavy execution of the same 110 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The internal clearance of 4T-413122 is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Open 4T-413122 units have no seals: the housing must seal both rows or the 1,600 r/min grease figure is meaningless once contamination enters.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 56 mm width, load spread and clearance logic of 4T-413122 are unit-specific.",
      "The 253/340 kN ratings and 37.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413122; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413122?",
        "a": "4T-413122 is a double-row tapered roller bearing of TDO (back-to-back) construction: 110 mm bore, 180 mm outside diameter and 56 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 253 kN, C0 340 kN, Cu 37.5 kN, grease limiting speed 1,600 r/min, oil speed 2,200 r/min, mass about 4.93 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 110 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413122 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413122 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 56 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413122 mean?",
        "a": "With no letter suffix, 413122 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-413122 list two speeds, 1,600 and 2,200 r/min?",
        "a": "The lower figure, 1,600 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413122 at 2,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413122",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-413122",
      "413122",
      "4T-413122"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423122",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423122",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 110,
    "D_mm": 180,
    "B_mm": 70,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 330,
    "static_load_kN": 485,
    "fatigue_load_limit_kN": 53,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 2200,
    "weight_g": 6380,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-423122 denotes the light-duty 430-family TDO double-row series — a 110 mm bore double-row tapered unit rated 330 kN basic dynamic and 485 kN static. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 423122 reads accordingly. Catalogue mass of 4T-423122 is 6.38 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. TDO construction means the two cone assemblies of 4T-423122 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 110 mm shaft. Axial clamping of the double cup must be uniform around the 180 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal",
      "steel-plant roller table and conveyor drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "Mount the 110 mm unit by induction heating (max 120 °C); at 6.38 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-423122 narrower and faster than the 432 heavy execution of the same 110 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 330 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The internal clearance of 4T-423122 is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 330 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 330/485 kN ratings and 53 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423122; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423122?",
        "a": "4T-423122 is a double-row tapered roller bearing of TDO (back-to-back) construction: 110 mm bore, 180 mm outside diameter and 70 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 330 kN, C0 485 kN, Cu 53 kN, grease limiting speed 1,600 r/min, oil speed 2,200 r/min, mass about 6.38 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 110 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423122 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423122 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 70 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423122 mean?",
        "a": "With no letter suffix, 423122 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-423122 list two speeds, 1,600 and 2,200 r/min?",
        "a": "The lower figure, 1,600 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423122 at 2,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423122",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-423122",
      "423122",
      "4T-423122"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430222XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430222XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 110,
    "D_mm": 200,
    "B_mm": 92,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 615,
    "static_load_kN": 865,
    "fatigue_load_limit_kN": 92.5,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 2000,
    "weight_g": 11400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430222XU is the NTN 4T catalogue entry for a 110×200×92 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Reading the designation: the last two digits 22 are the bore code, ×5 = 110 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. Double-row capacity is not twice a single-row bearing: the printed 615 kN C already accounts for load sharing between the two rows of 4T-430222XU, so apply it directly in the L10 calculation. The internal clearance of 4T-430222XU is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 92 mm overall width is the finished dimension. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-430222XU's locating position.",
    "applications": [
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "Mount the 110 mm unit by induction heating (max 120 °C); at 11.4 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430222XU narrower and faster than the 432 heavy execution of the same 110 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 92 mm width, load spread and clearance logic of 4T-430222XU are unit-specific.",
      "The 45.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-430222XU or the cones bottom out on the radius.",
      "The 615 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 615/865 kN ratings and 92.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430222XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430222XU?",
        "a": "4T-430222XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 110 mm bore, 200 mm outside diameter and 92 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 615 kN, C0 865 kN, Cu 92.5 kN, grease limiting speed 1,500 r/min, oil speed 2,000 r/min, mass about 11.4 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 110 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430222XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430222XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 92 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430222XU mean?",
        "a": "Suffix reading on 430222XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430222XU list two speeds, 1,500 and 2,000 r/min?",
        "a": "The lower figure, 1,500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430222XU at 2,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430222XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430222xu",
      "4t-430222xu",
      "430222XU",
      "4T-430222XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432222XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432222XU",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 110,
    "D_mm": 200,
    "B_mm": 121,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 800,
    "static_load_kN": 1210,
    "fatigue_load_limit_kN": 130,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 2000,
    "weight_g": 15800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-432222XU denotes the heavy-duty 432-family TDO double-row series — a 110 mm bore double-row tapered unit rated 800 kN basic dynamic and 1210 kN static. Reading the designation: the last two digits 22 are the bore code, ×5 = 110 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. The 7.3 kN of dynamic capacity per millimetre of bore summarises the 800 kN rating over the 110 mm bore — compare substitution candidates on this ratio and on the 121 mm width. The internal clearance of 4T-432222XU is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 121 mm overall width is the finished dimension. Mount 4T-432222XU as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "Mount the 110 mm unit by induction heating (max 120 °C); at 15.8 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432222XU its 121 mm width and 800 kN rating at the 110 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 130 kN Cu.",
      "An unloaded 4T-432222XU near 1,500 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 200 mm OD clamping uniformly around the circumference.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 121 mm width, load spread and clearance logic of 4T-432222XU are unit-specific.",
      "The 800/1210 kN ratings and 130 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432222XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432222XU?",
        "a": "4T-432222XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 110 mm bore, 200 mm outside diameter and 121 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 800 kN, C0 1210 kN, Cu 130 kN, grease limiting speed 1,500 r/min, oil speed 2,000 r/min, mass about 15.8 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 110 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432222XU belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432222XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 121 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432222XU mean?",
        "a": "Suffix reading on 432222XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432222XU list two speeds, 1,500 and 2,000 r/min?",
        "a": "The lower figure, 1,500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432222XU at 2,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432222XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432222xu",
      "4t-432222xu",
      "432222XU",
      "4T-432222XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430322U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430322U",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 110,
    "D_mm": 240,
    "B_mm": 118,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 910,
    "static_load_kN": 1170,
    "fatigue_load_limit_kN": 120,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1800,
    "weight_g": 23900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-430322U at 110 mm bore, 240 mm OD and 118 mm overall width, with a grease limiting speed of 1,400 r/min and an oil ceiling of 1,800 r/min. Reading the designation: the last two digits 22 are the bore code, ×5 = 110 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. Catalogue mass of 4T-430322U is 23.9 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. TDO construction means the two cone assemblies of 4T-430322U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 110 mm shaft. Induction heating to max 120 °C is the standard fitting method at this 110 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "large mixer and agitator shafts",
      "heavy gearbox and mill drive shafts",
      "crusher and screening-plant main shafts",
      "large fan and blower shafts with thrust reversal"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "Mount the 110 mm unit by induction heating (max 120 °C); at 23.9 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 430 light plan keeps 4T-430322U narrower and faster than the 432 heavy execution of the same 110 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 910 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "An unloaded 4T-430322U near 1,400 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Order by the full 430322U code including suffixes — U, X, DX, E1 and UTG variants share the 110 mm bore but are different articles with different internal geometry.",
      "The 910/1170 kN ratings and 120 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430322U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430322U?",
        "a": "4T-430322U is a double-row tapered roller bearing of TDO (back-to-back) construction: 110 mm bore, 240 mm outside diameter and 118 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 910 kN, C0 1170 kN, Cu 120 kN, grease limiting speed 1,400 r/min, oil speed 1,800 r/min, mass about 23.9 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 110 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430322U belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430322U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 118 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430322U mean?",
        "a": "Suffix reading on 430322U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430322U list two speeds, 1,400 and 1,800 r/min?",
        "a": "The lower figure, 1,400 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430322U at 1,800 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430322U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430322u",
      "4t-430322u",
      "430322U",
      "4T-430322U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432322U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432322U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 110,
    "D_mm": 240,
    "B_mm": 181,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1340,
    "static_load_kN": 1940,
    "fatigue_load_limit_kN": 199,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1800,
    "weight_g": 37400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-432322U at 110 mm bore, 240 mm OD and 181 mm overall width, with a grease limiting speed of 1,400 r/min and an oil ceiling of 1,800 r/min. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 110 mm bore the 432 execution carries a wider, heavier section than the 430. Speed planning uses both catalogue columns: grease 1,400 r/min is the mechanical ceiling, oil 1,800 r/min with oil lubrication — a 400 r/min margin at this size. TDO construction means the two cone assemblies of 4T-432322U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 110 mm shaft. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-432322U; the double cup must seat square across its full 181 mm width.",
    "applications": [
      "steel-plant roller table and conveyor drives",
      "marine winch and deck-machinery shafts",
      "bulk-handling stacker/reclaimer travel drives",
      "large mixer and agitator shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "Mount the 110 mm unit by induction heating (max 120 °C); at 37.4 kg a cocked lift damages the cages and ribs before the bearing ever runs.",
      "The 432 heavy plan gives 4T-432322U its 181 mm width and 1340 kN rating at the 110 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 199 kN Cu.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-432322U feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Open 4T-432322U units have no seals: the housing must seal both rows or the 1,400 r/min grease figure is meaningless once contamination enters.",
      "The internal clearance of 4T-432322U is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 1340/1940 kN ratings and 199 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432322U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432322U?",
        "a": "4T-432322U is a double-row tapered roller bearing of TDO (back-to-back) construction: 110 mm bore, 240 mm outside diameter and 181 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1340 kN, C0 1940 kN, Cu 199 kN, grease limiting speed 1,400 r/min, oil speed 1,800 r/min, mass about 37.4 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 110 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432322U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432322U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 181 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432322U mean?",
        "a": "Suffix reading on 432322U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432322U list two speeds, 1,400 and 1,800 r/min?",
        "a": "The lower figure, 1,400 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432322U at 1,800 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432322U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432322u",
      "4t-432322u",
      "432322U",
      "4T-432322U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323024",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323024",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 120,
    "D_mm": 180,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 255,
    "static_load_kN": 375,
    "fatigue_load_limit_kN": 40,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 2100,
    "weight_g": 4080,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323024 is the NTN 4T catalogue entry for a 120×180×46 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. With no letter suffix, 323024 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code. Grease relubrication at the 1,500 r/min limiting speed must reach both roller rows; sustaining 2,100 r/min needs an oil supply with defined flow through the double cup. TDO construction means the two cone assemblies of 4T-323024 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 120 mm shaft. Axial clamping of the double cup must be uniform around the 180 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 120 mm bore the 4T-323024 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 255 kN C level.",
      "The 432 heavy plan gives 4T-323024 its 46 mm width and 255 kN rating at the 120 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 40 kN Cu.",
      "An unloaded 4T-323024 near 1,500 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "At inspection do not mix the cone assemblies of 4T-323024 with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-323024 feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 255/375 kN ratings and 40 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323024; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323024?",
        "a": "4T-323024 is a double-row tapered roller bearing of TDO (back-to-back) construction: 120 mm bore, 180 mm outside diameter and 46 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 255 kN, C0 375 kN, Cu 40 kN, grease limiting speed 1,500 r/min, oil speed 2,100 r/min, mass about 4.08 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 120 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323024 belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323024 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 46 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323024 mean?",
        "a": "With no letter suffix, 323024 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-323024 list two speeds, 1,500 and 2,100 r/min?",
        "a": "The lower figure, 1,500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323024 at 2,100 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323024",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-323024",
      "323024",
      "4T-323024"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413024",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413024",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 120,
    "D_mm": 180,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 214,
    "static_load_kN": 298,
    "fatigue_load_limit_kN": 32,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 2100,
    "weight_g": 3850,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 120 mm shaft position as 4T-413024: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 46 mm. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 120 mm bore the 432 execution carries a wider, heavier section than the 430. Double-row capacity is not twice a single-row bearing: the printed 214 kN C already accounts for load sharing between the two rows of 4T-413024, so apply it directly in the L10 calculation. Because the unit is preset, mounting 4T-413024 resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Axial clamping of the double cup must be uniform around the 180 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 120 mm bore the 4T-413024 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 214 kN C level.",
      "The 430 light plan keeps 4T-413024 narrower and faster than the 432 heavy execution of the same 120 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 214 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-413024 feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 180 mm OD clamping uniformly around the circumference.",
      "The 214/298 kN ratings and 32 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413024; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413024?",
        "a": "4T-413024 is a double-row tapered roller bearing of TDO (back-to-back) construction: 120 mm bore, 180 mm outside diameter and 46 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 214 kN, C0 298 kN, Cu 32 kN, grease limiting speed 1,500 r/min, oil speed 2,100 r/min, mass about 3.85 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 120 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413024 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413024 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 46 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413024 mean?",
        "a": "With no letter suffix, 413024 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-413024 list two speeds, 1,500 and 2,100 r/min?",
        "a": "The lower figure, 1,500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413024 at 2,100 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413024",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-413024",
      "413024",
      "4T-413024"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423024",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423024",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 120,
    "D_mm": 180,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 255,
    "static_load_kN": 375,
    "fatigue_load_limit_kN": 40,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 2100,
    "weight_g": 4350,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-423024 denotes the light-duty 430-family TDO double-row series — a 120 mm bore double-row tapered unit rated 255 kN basic dynamic and 375 kN static. Unlike a pair of single-row bearings, the TDO unit of 4T-423024 integrates both rows in one article: the 58 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The 2.1 kN of dynamic capacity per millimetre of bore summarises the 255 kN rating over the 120 mm bore — compare substitution candidates on this ratio and on the 58 mm width. TDO construction means the two cone assemblies of 4T-423024 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 120 mm shaft. Mount 4T-423024 as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 120 mm bore the 4T-423024 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 255 kN C level.",
      "The 430 light plan keeps 4T-423024 narrower and faster than the 432 heavy execution of the same 120 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Grease packs must leave free volume across the 58 mm width; over-greasing a unit churning near the 2,100 r/min oil-band speed raises temperature and expels the grease.",
      "Order by the full 423024 code including suffixes — U, X, DX, E1 and UTG variants share the 120 mm bore but are different articles with different internal geometry.",
      "An unloaded 4T-423024 near 1,500 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 255/375 kN ratings and 40 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423024; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423024?",
        "a": "4T-423024 is a double-row tapered roller bearing of TDO (back-to-back) construction: 120 mm bore, 180 mm outside diameter and 58 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 255 kN, C0 375 kN, Cu 40 kN, grease limiting speed 1,500 r/min, oil speed 2,100 r/min, mass about 4.35 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 120 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423024 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423024 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 58 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423024 mean?",
        "a": "With no letter suffix, 423024 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-423024 list two speeds, 1,500 and 2,100 r/min?",
        "a": "The lower figure, 1,500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423024 at 2,100 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423024",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-423024",
      "423024",
      "4T-423024"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323124",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323124",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 120,
    "D_mm": 200,
    "B_mm": 62,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 415,
    "static_load_kN": 610,
    "fatigue_load_limit_kN": 64.5,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 2000,
    "weight_g": 7820,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 120 mm shaft needing a compact two-direction thrust location, NTN lists 4T-323124, a TDO double-row 4T unit of 415 kN C and 610 kN C0 in the heavy-duty 432-family TDO double-row series. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 120 mm bore the 432 execution carries a wider, heavier section than the 430. Selection: C 415 kN against C0 610 kN gives a C0/C ratio of 1.47; the two rows of 4T-323124 share the combined load as one bearing position. TDO construction means the two cone assemblies of 4T-323124 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 120 mm shaft. With a rotating shaft a m6/n6 seat on the 120 mm journal and a located cup in the housing are typical practice for 4T-323124.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 120 mm bore the 4T-323124 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 415 kN C level.",
      "The 432 heavy plan gives 4T-323124 its 62 mm width and 415 kN rating at the 120 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 64.5 kN Cu.",
      "Open 4T-323124 units have no seals: the housing must seal both rows or the 1,500 r/min grease figure is meaningless once contamination enters.",
      "The 40.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-323124 or the cones bottom out on the radius.",
      "Open 4T-323124 units have no seals: the housing must seal both rows or the 1,500 r/min grease figure is meaningless once contamination enters.",
      "The 415/610 kN ratings and 64.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323124; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323124?",
        "a": "4T-323124 is a double-row tapered roller bearing of TDO (back-to-back) construction: 120 mm bore, 200 mm outside diameter and 62 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 415 kN, C0 610 kN, Cu 64.5 kN, grease limiting speed 1,500 r/min, oil speed 2,000 r/min, mass about 7.82 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 120 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323124 belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323124 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 62 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323124 mean?",
        "a": "With no letter suffix, 323124 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-323124 list two speeds, 1,500 and 2,000 r/min?",
        "a": "The lower figure, 1,500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323124 at 2,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323124",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-323124",
      "323124",
      "4T-323124"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413124",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413124",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 120,
    "D_mm": 200,
    "B_mm": 62,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 291,
    "static_load_kN": 435,
    "fatigue_load_limit_kN": 46,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 2000,
    "weight_g": 7240,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-413124 at 120 mm bore, 200 mm OD and 62 mm overall width, with a grease limiting speed of 1,500 r/min and an oil ceiling of 2,000 r/min. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 413124 reads accordingly. The fatigue load limit Cu printed for 4T-413124 is 46 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. Because the unit is preset, mounting 4T-413124 resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. With a rotating shaft a m6/n6 seat on the 120 mm journal and a located cup in the housing are typical practice for 4T-413124.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 120 mm bore the 4T-413124 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 291 kN C level.",
      "The 430 light plan keeps 4T-413124 narrower and faster than the 432 heavy execution of the same 120 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-413124 feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 291 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 291 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 291/435 kN ratings and 46 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413124; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413124?",
        "a": "4T-413124 is a double-row tapered roller bearing of TDO (back-to-back) construction: 120 mm bore, 200 mm outside diameter and 62 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 291 kN, C0 435 kN, Cu 46 kN, grease limiting speed 1,500 r/min, oil speed 2,000 r/min, mass about 7.24 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 120 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413124 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413124 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 62 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413124 mean?",
        "a": "With no letter suffix, 413124 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-413124 list two speeds, 1,500 and 2,000 r/min?",
        "a": "The lower figure, 1,500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413124 at 2,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413124",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-413124",
      "413124",
      "4T-413124"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423124",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423124",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 120,
    "D_mm": 200,
    "B_mm": 78,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 415,
    "static_load_kN": 610,
    "fatigue_load_limit_kN": 64.5,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 2000,
    "weight_g": 8690,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423124 is the NTN 4T catalogue entry for a 120×200×78 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Reading the designation: the last two digits 24 are the bore code, ×5 = 120 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. Selection: C 415 kN against C0 610 kN gives a C0/C ratio of 1.47; the two rows of 4T-423124 share the combined load as one bearing position. TDO construction means the two cone assemblies of 4T-423124 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 120 mm shaft. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-423124; the double cup must seat square across its full 78 mm width.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 120 mm bore the 4T-423124 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 415 kN C level.",
      "The 430 light plan keeps 4T-423124 narrower and faster than the 432 heavy execution of the same 120 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-423124 near 1,500 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 78 mm width, load spread and clearance logic of 4T-423124 are unit-specific.",
      "The 40.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-423124 or the cones bottom out on the radius.",
      "The 415/610 kN ratings and 64.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423124; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423124?",
        "a": "4T-423124 is a double-row tapered roller bearing of TDO (back-to-back) construction: 120 mm bore, 200 mm outside diameter and 78 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 415 kN, C0 610 kN, Cu 64.5 kN, grease limiting speed 1,500 r/min, oil speed 2,000 r/min, mass about 8.69 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 120 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423124 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423124 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 78 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423124 mean?",
        "a": "With no letter suffix, 423124 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-423124 list two speeds, 1,500 and 2,000 r/min?",
        "a": "The lower figure, 1,500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423124 at 2,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423124",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-423124",
      "423124",
      "4T-423124"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430224XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430224XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 120,
    "D_mm": 215,
    "B_mm": 97,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 660,
    "static_load_kN": 940,
    "fatigue_load_limit_kN": 98.5,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1900,
    "weight_g": 13800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430224XU is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 120×215×97 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-430224XU integrates both rows in one article: the 97 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Speed planning uses both catalogue columns: grease 1,400 r/min is the mechanical ceiling, oil 1,900 r/min with oil lubrication — a 500 r/min margin at this size. Because the unit is preset, mounting 4T-430224XU resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. At 660 kN C the unit offers about 5.5 kN per millimetre of the 120 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 1,900 r/min.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 120 mm bore the 4T-430224XU unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 660 kN C level.",
      "The 430 light plan keeps 4T-430224XU narrower and faster than the 432 heavy execution of the same 120 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 215 mm OD clamping uniformly around the circumference.",
      "The internal clearance of 4T-430224XU is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "An unloaded 4T-430224XU near 1,400 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 660/940 kN ratings and 98.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430224XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430224XU?",
        "a": "4T-430224XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 120 mm bore, 215 mm outside diameter and 97 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 660 kN, C0 940 kN, Cu 98.5 kN, grease limiting speed 1,400 r/min, oil speed 1,900 r/min, mass about 13.8 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 120 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430224XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430224XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 97 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430224XU mean?",
        "a": "Suffix reading on 430224XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430224XU list two speeds, 1,400 and 1,900 r/min?",
        "a": "The lower figure, 1,400 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430224XU at 1,900 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430224XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430224xu",
      "4t-430224xu",
      "430224XU",
      "4T-430224XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432224XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432224XU",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 120,
    "D_mm": 215,
    "B_mm": 132,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 875,
    "static_load_kN": 1360,
    "fatigue_load_limit_kN": 143,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1900,
    "weight_g": 19200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-432224XU is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 120×215×132 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-432224XU integrates both rows in one article: the 132 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The fatigue load limit Cu printed for 4T-432224XU is 143 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-432224XU face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 120 mm shaft. Axial clamping of the double cup must be uniform around the 215 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 120 mm bore the 4T-432224XU unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 875 kN C level.",
      "The 432 heavy plan gives 4T-432224XU its 132 mm width and 875 kN rating at the 120 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 143 kN Cu.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 132 mm width, load spread and clearance logic of 4T-432224XU are unit-specific.",
      "An unloaded 4T-432224XU near 1,400 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Grease packs must leave free volume across the 132 mm width; over-greasing a unit churning near the 1,900 r/min oil-band speed raises temperature and expels the grease.",
      "The 875/1360 kN ratings and 143 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432224XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432224XU?",
        "a": "4T-432224XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 120 mm bore, 215 mm outside diameter and 132 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 875 kN, C0 1360 kN, Cu 143 kN, grease limiting speed 1,400 r/min, oil speed 1,900 r/min, mass about 19.2 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 120 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432224XU belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432224XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 132 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432224XU mean?",
        "a": "Suffix reading on 432224XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432224XU list two speeds, 1,400 and 1,900 r/min?",
        "a": "The lower figure, 1,400 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432224XU at 1,900 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432224XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432224xu",
      "4t-432224xu",
      "432224XU",
      "4T-432224XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430324XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430324XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 120,
    "D_mm": 260,
    "B_mm": 128,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1060,
    "static_load_kN": 1390,
    "fatigue_load_limit_kN": 139,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1700,
    "weight_g": 30300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-430324XU denotes the light-duty 430-family TDO double-row series — a 120 mm bore double-row tapered unit rated 1060 kN basic dynamic and 1390 kN static. Reading the designation: the last two digits 24 are the bore code, ×5 = 120 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. The 70.0 mm radial section over the 120 mm bore carries two roller rows across the 128 mm width; abutment shoulders must clear both cone bores and the double-cup OD. The internal clearance of 4T-430324XU is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 128 mm overall width is the finished dimension. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-430324XU's locating position.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 120 mm bore the 4T-430324XU unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1060 kN C level.",
      "The 430 light plan keeps 4T-430324XU narrower and faster than the 432 heavy execution of the same 120 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 1060 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 70.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-430324XU or the cones bottom out on the radius.",
      "The 1060 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 1060/1390 kN ratings and 139 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430324XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430324XU?",
        "a": "4T-430324XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 120 mm bore, 260 mm outside diameter and 128 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1060 kN, C0 1390 kN, Cu 139 kN, grease limiting speed 1,200 r/min, oil speed 1,700 r/min, mass about 30.3 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 120 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430324XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430324XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 128 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430324XU mean?",
        "a": "Suffix reading on 430324XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430324XU list two speeds, 1,200 and 1,700 r/min?",
        "a": "The lower figure, 1,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430324XU at 1,700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430324XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430324xu",
      "4t-430324xu",
      "430324XU",
      "4T-430324XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432324U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432324U",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 120,
    "D_mm": 260,
    "B_mm": 188,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1550,
    "static_load_kN": 2270,
    "fatigue_load_limit_kN": 228,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1700,
    "weight_g": 47000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-432324U is the NTN 4T catalogue entry for a 120×260×188 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 432324U reads accordingly. Catalogue mass of 4T-432324U is 47 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. TDO construction means the two cone assemblies of 4T-432324U face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 120 mm shaft. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-432324U's locating position.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 120 mm bore the 4T-432324U unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1550 kN C level.",
      "The 432 heavy plan gives 4T-432324U its 188 mm width and 1550 kN rating at the 120 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 228 kN Cu.",
      "An unloaded 4T-432324U near 1,200 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Order by the full 432324U code including suffixes — U, X, DX, E1 and UTG variants share the 120 mm bore but are different articles with different internal geometry.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 260 mm OD clamping uniformly around the circumference.",
      "The 1550/2270 kN ratings and 228 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432324U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432324U?",
        "a": "4T-432324U is a double-row tapered roller bearing of TDO (back-to-back) construction: 120 mm bore, 260 mm outside diameter and 188 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1550 kN, C0 2270 kN, Cu 228 kN, grease limiting speed 1,200 r/min, oil speed 1,700 r/min, mass about 47 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 120 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432324U belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432324U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 188 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432324U mean?",
        "a": "Suffix reading on 432324U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432324U list two speeds, 1,200 and 1,700 r/min?",
        "a": "The lower figure, 1,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432324U at 1,700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432324U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432324u",
      "4t-432324u",
      "432324U",
      "4T-432324U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323026",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323026",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 130,
    "D_mm": 200,
    "B_mm": 52,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 325,
    "static_load_kN": 490,
    "fatigue_load_limit_kN": 51.5,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1900,
    "weight_g": 5740,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 130 mm shaft needing a compact two-direction thrust location, NTN lists 4T-323026, a TDO double-row 4T unit of 325 kN C and 490 kN C0 in the heavy-duty 432-family TDO double-row series. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 130 mm bore the 432 execution carries a wider, heavier section than the 430. The 35.0 mm radial section over the 130 mm bore carries two roller rows across the 52 mm width; abutment shoulders must clear both cone bores and the double-cup OD. TDO construction means the two cone assemblies of 4T-323026 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 130 mm shaft. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-323026; the double cup must seat square across its full 52 mm width.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 130 mm bore the 4T-323026 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 325 kN C level.",
      "The 432 heavy plan gives 4T-323026 its 52 mm width and 325 kN rating at the 130 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 51.5 kN Cu.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 52 mm width, load spread and clearance logic of 4T-323026 are unit-specific.",
      "An unloaded 4T-323026 near 1,400 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "At inspection do not mix the cone assemblies of 4T-323026 with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 325/490 kN ratings and 51.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323026; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323026?",
        "a": "4T-323026 is a double-row tapered roller bearing of TDO (back-to-back) construction: 130 mm bore, 200 mm outside diameter and 52 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 325 kN, C0 490 kN, Cu 51.5 kN, grease limiting speed 1,400 r/min, oil speed 1,900 r/min, mass about 5.74 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 130 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323026 belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323026 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 52 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323026 mean?",
        "a": "With no letter suffix, 323026 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-323026 list two speeds, 1,400 and 1,900 r/min?",
        "a": "The lower figure, 1,400 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323026 at 1,900 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323026",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-323026",
      "323026",
      "4T-323026"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413026",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413026",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 130,
    "D_mm": 200,
    "B_mm": 52,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 249,
    "static_load_kN": 365,
    "fatigue_load_limit_kN": 38.5,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1900,
    "weight_g": 5550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-413026 at 130 mm bore, 200 mm OD and 52 mm overall width, with a grease limiting speed of 1,400 r/min and an oil ceiling of 1,900 r/min. Unlike a pair of single-row bearings, the TDO unit of 4T-413026 integrates both rows in one article: the 52 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Speed planning uses both catalogue columns: grease 1,400 r/min is the mechanical ceiling, oil 1,900 r/min with oil lubrication — a 500 r/min margin at this size. Because the unit is preset, mounting 4T-413026 resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-413026; the double cup must seat square across its full 52 mm width.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 130 mm bore the 4T-413026 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 249 kN C level.",
      "The 430 light plan keeps 4T-413026 narrower and faster than the 432 heavy execution of the same 130 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-413026 near 1,400 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 200 mm OD clamping uniformly around the circumference.",
      "An unloaded 4T-413026 near 1,400 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 249/365 kN ratings and 38.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413026; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413026?",
        "a": "4T-413026 is a double-row tapered roller bearing of TDO (back-to-back) construction: 130 mm bore, 200 mm outside diameter and 52 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 249 kN, C0 365 kN, Cu 38.5 kN, grease limiting speed 1,400 r/min, oil speed 1,900 r/min, mass about 5.55 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 130 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413026 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413026 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 52 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413026 mean?",
        "a": "With no letter suffix, 413026 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-413026 list two speeds, 1,400 and 1,900 r/min?",
        "a": "The lower figure, 1,400 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413026 at 1,900 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413026",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-413026",
      "413026",
      "4T-413026"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423026",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423026",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 130,
    "D_mm": 200,
    "B_mm": 65,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 325,
    "static_load_kN": 490,
    "fatigue_load_limit_kN": 51.5,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1900,
    "weight_g": 6620,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423026 is the NTN 4T catalogue entry for a 130×200×65 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 423026 reads accordingly. The fatigue load limit Cu printed for 4T-423026 is 51.5 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-423026 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 130 mm shaft. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-423026's locating position.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 130 mm bore the 4T-423026 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 325 kN C level.",
      "The 430 light plan keeps 4T-423026 narrower and faster than the 432 heavy execution of the same 130 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Open 4T-423026 units have no seals: the housing must seal both rows or the 1,400 r/min grease figure is meaningless once contamination enters.",
      "Open 4T-423026 units have no seals: the housing must seal both rows or the 1,400 r/min grease figure is meaningless once contamination enters.",
      "Order by the full 423026 code including suffixes — U, X, DX, E1 and UTG variants share the 130 mm bore but are different articles with different internal geometry.",
      "The 325/490 kN ratings and 51.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423026; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423026?",
        "a": "4T-423026 is a double-row tapered roller bearing of TDO (back-to-back) construction: 130 mm bore, 200 mm outside diameter and 65 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 325 kN, C0 490 kN, Cu 51.5 kN, grease limiting speed 1,400 r/min, oil speed 1,900 r/min, mass about 6.62 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 130 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423026 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423026 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 65 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423026 mean?",
        "a": "With no letter suffix, 423026 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-423026 list two speeds, 1,400 and 1,900 r/min?",
        "a": "The lower figure, 1,400 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423026 at 1,900 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423026",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-423026",
      "423026",
      "4T-423026"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323126",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323126",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 130,
    "D_mm": 210,
    "B_mm": 64,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 455,
    "static_load_kN": 675,
    "fatigue_load_limit_kN": 70.5,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1800,
    "weight_g": 8380,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323126 is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 130×210×64 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-323126 integrates both rows in one article: the 64 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The 3.5 kN of dynamic capacity per millimetre of bore summarises the 455 kN rating over the 130 mm bore — compare substitution candidates on this ratio and on the 64 mm width. TDO construction means the two cone assemblies of 4T-323126 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 130 mm shaft. At 455 kN C the unit offers about 3.5 kN per millimetre of the 130 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 1,800 r/min.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 130 mm bore the 4T-323126 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 455 kN C level.",
      "The 432 heavy plan gives 4T-323126 its 64 mm width and 455 kN rating at the 130 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 70.5 kN Cu.",
      "At inspection do not mix the cone assemblies of 4T-323126 with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Grease packs must leave free volume across the 64 mm width; over-greasing a unit churning near the 1,800 r/min oil-band speed raises temperature and expels the grease.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 210 mm OD clamping uniformly around the circumference.",
      "The 455/675 kN ratings and 70.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323126; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323126?",
        "a": "4T-323126 is a double-row tapered roller bearing of TDO (back-to-back) construction: 130 mm bore, 210 mm outside diameter and 64 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 455 kN, C0 675 kN, Cu 70.5 kN, grease limiting speed 1,400 r/min, oil speed 1,800 r/min, mass about 8.38 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 130 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323126 belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323126 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 64 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323126 mean?",
        "a": "With no letter suffix, 323126 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-323126 list two speeds, 1,400 and 1,800 r/min?",
        "a": "The lower figure, 1,400 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323126 at 1,800 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323126",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-323126",
      "323126",
      "4T-323126"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413126",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413126",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 130,
    "D_mm": 210,
    "B_mm": 64,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 350,
    "static_load_kN": 485,
    "fatigue_load_limit_kN": 50.5,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1800,
    "weight_g": 7830,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413126 belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Reading the designation: the last two digits 26 are the bore code, ×5 = 130 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. Double-row capacity is not twice a single-row bearing: the printed 350 kN C already accounts for load sharing between the two rows of 4T-413126, so apply it directly in the L10 calculation. Because the unit is preset, mounting 4T-413126 resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. At 350 kN C the unit offers about 2.7 kN per millimetre of the 130 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 1,800 r/min.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 130 mm bore the 4T-413126 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 350 kN C level.",
      "The 430 light plan keeps 4T-413126 narrower and faster than the 432 heavy execution of the same 130 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 40.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-413126 or the cones bottom out on the radius.",
      "At inspection do not mix the cone assemblies of 4T-413126 with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 40.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-413126 or the cones bottom out on the radius.",
      "The 350/485 kN ratings and 50.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413126; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413126?",
        "a": "4T-413126 is a double-row tapered roller bearing of TDO (back-to-back) construction: 130 mm bore, 210 mm outside diameter and 64 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 350 kN, C0 485 kN, Cu 50.5 kN, grease limiting speed 1,400 r/min, oil speed 1,800 r/min, mass about 7.83 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 130 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413126 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413126 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 64 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413126 mean?",
        "a": "With no letter suffix, 413126 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-413126 list two speeds, 1,400 and 1,800 r/min?",
        "a": "The lower figure, 1,400 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413126 at 1,800 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413126",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-413126",
      "413126",
      "4T-413126"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423126",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423126",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 130,
    "D_mm": 210,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 455,
    "static_load_kN": 675,
    "fatigue_load_limit_kN": 70.5,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1800,
    "weight_g": 9400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 130 mm shaft needing a compact two-direction thrust location, NTN lists 4T-423126, a TDO double-row 4T unit of 455 kN C and 675 kN C0 in the light-duty 430-family TDO double-row series. With no letter suffix, 423126 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code. The 3.5 kN of dynamic capacity per millimetre of bore summarises the 455 kN rating over the 130 mm bore — compare substitution candidates on this ratio and on the 80 mm width. TDO construction means the two cone assemblies of 4T-423126 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 130 mm shaft. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-423126 are ground as a unit.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 130 mm bore the 4T-423126 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 455 kN C level.",
      "The 430 light plan keeps 4T-423126 narrower and faster than the 432 heavy execution of the same 130 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 80 mm width, load spread and clearance logic of 4T-423126 are unit-specific.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-423126 feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The internal clearance of 4T-423126 is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 455/675 kN ratings and 70.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423126; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423126?",
        "a": "4T-423126 is a double-row tapered roller bearing of TDO (back-to-back) construction: 130 mm bore, 210 mm outside diameter and 80 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 455 kN, C0 675 kN, Cu 70.5 kN, grease limiting speed 1,400 r/min, oil speed 1,800 r/min, mass about 9.4 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 130 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423126 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423126 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 80 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423126 mean?",
        "a": "With no letter suffix, 423126 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-423126 list two speeds, 1,400 and 1,800 r/min?",
        "a": "The lower figure, 1,400 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423126 at 1,800 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423126",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-423126",
      "423126",
      "4T-423126"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430226XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430226XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 130,
    "D_mm": 230,
    "B_mm": 98,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 710,
    "static_load_kN": 1010,
    "fatigue_load_limit_kN": 103,
    "limiting_speed_rpm": 1300,
    "max_rpm": 1300,
    "speed_oil_rpm": 1700,
    "weight_g": 15300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-430226XU at 130 mm bore, 230 mm OD and 98 mm overall width, with a grease limiting speed of 1,300 r/min and an oil ceiling of 1,700 r/min. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 130 mm bore the 432 execution carries a wider, heavier section than the 430. Selection: C 710 kN against C0 1010 kN gives a C0/C ratio of 1.42; the two rows of 4T-430226XU share the combined load as one bearing position. TDO construction means the two cone assemblies of 4T-430226XU face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 130 mm shaft. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 130 mm size before ordering 4T-430226XU.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 130 mm bore the 4T-430226XU unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 710 kN C level.",
      "The 430 light plan keeps 4T-430226XU narrower and faster than the 432 heavy execution of the same 130 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-430226XU feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Open 4T-430226XU units have no seals: the housing must seal both rows or the 1,300 r/min grease figure is meaningless once contamination enters.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 98 mm width, load spread and clearance logic of 4T-430226XU are unit-specific.",
      "The 710/1010 kN ratings and 103 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430226XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430226XU?",
        "a": "4T-430226XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 130 mm bore, 230 mm outside diameter and 98 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 710 kN, C0 1010 kN, Cu 103 kN, grease limiting speed 1,300 r/min, oil speed 1,700 r/min, mass about 15.3 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 130 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430226XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430226XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 98 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430226XU mean?",
        "a": "Suffix reading on 430226XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430226XU list two speeds, 1,300 and 1,700 r/min?",
        "a": "The lower figure, 1,300 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430226XU at 1,700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430226XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430226xu",
      "4t-430226xu",
      "430226XU",
      "4T-430226XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432226XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432226XU",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 130,
    "D_mm": 230,
    "B_mm": 145,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1010,
    "static_load_kN": 1630,
    "fatigue_load_limit_kN": 167,
    "limiting_speed_rpm": 1300,
    "max_rpm": 1300,
    "speed_oil_rpm": 1700,
    "weight_g": 24000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-432226XU at 130 mm bore, 230 mm OD and 145 mm overall width, with a grease limiting speed of 1,300 r/min and an oil ceiling of 1,700 r/min. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 130 mm bore the 432 execution carries a wider, heavier section than the 430. Axial capacity is bidirectional because the rows are opposed: 4T-432226XU locates the shaft in both directions with C0 1630 kN behind the static check of the more heavily loaded row. The internal clearance of 4T-432226XU is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 145 mm overall width is the finished dimension. The open unit carries no seals; the housing of 4T-432226XU must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 130 mm bore the 4T-432226XU unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1010 kN C level.",
      "The 432 heavy plan gives 4T-432226XU its 145 mm width and 1010 kN rating at the 130 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 167 kN Cu.",
      "The internal clearance of 4T-432226XU is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Order by the full 432226XU code including suffixes — U, X, DX, E1 and UTG variants share the 130 mm bore but are different articles with different internal geometry.",
      "Open 4T-432226XU units have no seals: the housing must seal both rows or the 1,300 r/min grease figure is meaningless once contamination enters.",
      "The 1010/1630 kN ratings and 167 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432226XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432226XU?",
        "a": "4T-432226XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 130 mm bore, 230 mm outside diameter and 145 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1010 kN, C0 1630 kN, Cu 167 kN, grease limiting speed 1,300 r/min, oil speed 1,700 r/min, mass about 24 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 130 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432226XU belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432226XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 145 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432226XU mean?",
        "a": "Suffix reading on 432226XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432226XU list two speeds, 1,300 and 1,700 r/min?",
        "a": "The lower figure, 1,300 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432226XU at 1,700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432226XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432226xu",
      "4t-432226xu",
      "432226XU",
      "4T-432226XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430326XUUTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430326XUUTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 130,
    "D_mm": 280,
    "B_mm": 137,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1430,
    "static_load_kN": 1660,
    "fatigue_load_limit_kN": 162,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1600,
    "weight_g": 37900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430326XUUTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 130×280×137 mm. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 430326XUUTG reads accordingly. Grease relubrication at the 1,200 r/min limiting speed must reach both roller rows; sustaining 1,600 r/min needs an oil supply with defined flow through the double cup. The internal clearance of 4T-430326XUUTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 137 mm overall width is the finished dimension. Axial clamping of the double cup must be uniform around the 280 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 130 mm bore the 4T-430326XUUTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1430 kN C level.",
      "The 430 light plan keeps 4T-430326XUUTG narrower and faster than the 432 heavy execution of the same 130 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 280 mm OD clamping uniformly around the circumference.",
      "The 75.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-430326XUUTG or the cones bottom out on the radius.",
      "At inspection do not mix the cone assemblies of 4T-430326XUUTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 1430/1660 kN ratings and 162 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430326XUUTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430326XUUTG?",
        "a": "4T-430326XUUTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 130 mm bore, 280 mm outside diameter and 137 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1430 kN, C0 1660 kN, Cu 162 kN, grease limiting speed 1,200 r/min, oil speed 1,600 r/min, mass about 37.9 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 130 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430326XUUTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430326XUUTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 137 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430326XUUTG mean?",
        "a": "Suffix reading on 430326XUUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430326XUUTG list two speeds, 1,200 and 1,600 r/min?",
        "a": "The lower figure, 1,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430326XUUTG at 1,600 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430326XUUTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430326xuutg",
      "4t-430326xuutg",
      "＊430326xuutg",
      "430326XUUTG",
      "4T-430326XUUTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432326UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432326UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 130,
    "D_mm": 280,
    "B_mm": 205,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1960,
    "static_load_kN": 2470,
    "fatigue_load_limit_kN": 243,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1600,
    "weight_g": 56600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-432326UTG belongs to the heavy-duty 432-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Unlike a pair of single-row bearings, the TDO unit of 4T-432326UTG integrates both rows in one article: the 205 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The fatigue load limit Cu printed for 4T-432326UTG is 243 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. Because the unit is preset, mounting 4T-432326UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. With a rotating shaft a m6/n6 seat on the 130 mm journal and a located cup in the housing are typical practice for 4T-432326UTG.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 130 mm bore the 4T-432326UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1960 kN C level.",
      "The 432 heavy plan gives 4T-432326UTG its 205 mm width and 1960 kN rating at the 130 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 243 kN Cu.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 280 mm OD clamping uniformly around the circumference.",
      "Open 4T-432326UTG units have no seals: the housing must seal both rows or the 1,200 r/min grease figure is meaningless once contamination enters.",
      "Grease packs must leave free volume across the 205 mm width; over-greasing a unit churning near the 1,600 r/min oil-band speed raises temperature and expels the grease.",
      "The 1960/2470 kN ratings and 243 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432326UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432326UTG?",
        "a": "4T-432326UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 130 mm bore, 280 mm outside diameter and 205 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1960 kN, C0 2470 kN, Cu 243 kN, grease limiting speed 1,200 r/min, oil speed 1,600 r/min, mass about 56.6 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 130 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432326UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432326UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 205 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432326UTG mean?",
        "a": "Suffix reading on 432326UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432326UTG list two speeds, 1,200 and 1,600 r/min?",
        "a": "The lower figure, 1,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432326UTG at 1,600 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432326UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432326utg",
      "4t-432326utg",
      "＊432326utg",
      "432326UTG",
      "4T-432326UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323028",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323028",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 140,
    "D_mm": 210,
    "B_mm": 53,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 335,
    "static_load_kN": 535,
    "fatigue_load_limit_kN": 55,
    "limiting_speed_rpm": 1300,
    "max_rpm": 1300,
    "speed_oil_rpm": 1800,
    "weight_g": 6360,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323028 is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 140×210×53 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-323028 integrates both rows in one article: the 53 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Axial capacity is bidirectional because the rows are opposed: 4T-323028 locates the shaft in both directions with C0 535 kN behind the static check of the more heavily loaded row. TDO construction means the two cone assemblies of 4T-323028 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 140 mm shaft. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-323028 are ground as a unit.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 140 mm bore the 4T-323028 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 335 kN C level.",
      "The 432 heavy plan gives 4T-323028 its 53 mm width and 335 kN rating at the 140 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 55 kN Cu.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 210 mm OD clamping uniformly around the circumference.",
      "The internal clearance of 4T-323028 is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Grease packs must leave free volume across the 53 mm width; over-greasing a unit churning near the 1,800 r/min oil-band speed raises temperature and expels the grease.",
      "The 335/535 kN ratings and 55 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323028; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323028?",
        "a": "4T-323028 is a double-row tapered roller bearing of TDO (back-to-back) construction: 140 mm bore, 210 mm outside diameter and 53 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 335 kN, C0 535 kN, Cu 55 kN, grease limiting speed 1,300 r/min, oil speed 1,800 r/min, mass about 6.36 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 140 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323028 belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323028 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 53 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323028 mean?",
        "a": "With no letter suffix, 323028 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-323028 list two speeds, 1,300 and 1,800 r/min?",
        "a": "The lower figure, 1,300 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323028 at 1,800 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323028",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-323028",
      "323028",
      "4T-323028"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413028",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413028",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 140,
    "D_mm": 210,
    "B_mm": 53,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 291,
    "static_load_kN": 415,
    "fatigue_load_limit_kN": 43,
    "limiting_speed_rpm": 1300,
    "max_rpm": 1300,
    "speed_oil_rpm": 1800,
    "weight_g": 5730,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413028 belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 413028 reads accordingly. Grease relubrication at the 1,300 r/min limiting speed must reach both roller rows; sustaining 1,800 r/min needs an oil supply with defined flow through the double cup. Because the unit is preset, mounting 4T-413028 resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-413028 are ground as a unit.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 140 mm bore the 4T-413028 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 291 kN C level.",
      "The 430 light plan keeps 4T-413028 narrower and faster than the 432 heavy execution of the same 140 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 53 mm width, load spread and clearance logic of 4T-413028 are unit-specific.",
      "The 35.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-413028 or the cones bottom out on the radius.",
      "Order by the full 413028 code including suffixes — U, X, DX, E1 and UTG variants share the 140 mm bore but are different articles with different internal geometry.",
      "The 291/415 kN ratings and 43 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413028; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413028?",
        "a": "4T-413028 is a double-row tapered roller bearing of TDO (back-to-back) construction: 140 mm bore, 210 mm outside diameter and 53 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 291 kN, C0 415 kN, Cu 43 kN, grease limiting speed 1,300 r/min, oil speed 1,800 r/min, mass about 5.73 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 140 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413028 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413028 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 53 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413028 mean?",
        "a": "With no letter suffix, 413028 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-413028 list two speeds, 1,300 and 1,800 r/min?",
        "a": "The lower figure, 1,300 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413028 at 1,800 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413028",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-413028",
      "413028",
      "4T-413028"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423028",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423028",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 140,
    "D_mm": 210,
    "B_mm": 66,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 335,
    "static_load_kN": 535,
    "fatigue_load_limit_kN": 55,
    "limiting_speed_rpm": 1300,
    "max_rpm": 1300,
    "speed_oil_rpm": 1800,
    "weight_g": 7070,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 140 mm shaft needing a compact two-direction thrust location, NTN lists 4T-423028, a TDO double-row 4T unit of 335 kN C and 535 kN C0 in the light-duty 430-family TDO double-row series. Reading the designation: the last two digits 28 are the bore code, ×5 = 140 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. Double-row capacity is not twice a single-row bearing: the printed 335 kN C already accounts for load sharing between the two rows of 4T-423028, so apply it directly in the L10 calculation. TDO construction means the two cone assemblies of 4T-423028 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 140 mm shaft. The open unit carries no seals; the housing of 4T-423028 must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 140 mm bore the 4T-423028 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 335 kN C level.",
      "The 430 light plan keeps 4T-423028 narrower and faster than the 432 heavy execution of the same 140 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "At inspection do not mix the cone assemblies of 4T-423028 with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 335 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-423028 feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 335/535 kN ratings and 55 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423028; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423028?",
        "a": "4T-423028 is a double-row tapered roller bearing of TDO (back-to-back) construction: 140 mm bore, 210 mm outside diameter and 66 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 335 kN, C0 535 kN, Cu 55 kN, grease limiting speed 1,300 r/min, oil speed 1,800 r/min, mass about 7.07 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 140 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423028 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423028 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 66 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423028 mean?",
        "a": "With no letter suffix, 423028 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-423028 list two speeds, 1,300 and 1,800 r/min?",
        "a": "The lower figure, 1,300 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423028 at 1,800 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423028",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-423028",
      "423028",
      "4T-423028"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323128",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323128",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 140,
    "D_mm": 225,
    "B_mm": 68,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 435,
    "static_load_kN": 650,
    "fatigue_load_limit_kN": 66,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1700,
    "weight_g": 9820,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 140 mm shaft position as 4T-323128: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 68 mm. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 323128 reads accordingly. The fatigue load limit Cu printed for 4T-323128 is 66 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-323128 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 140 mm shaft. Mount 4T-323128 as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 140 mm bore the 4T-323128 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 435 kN C level.",
      "The 432 heavy plan gives 4T-323128 its 68 mm width and 435 kN rating at the 140 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 66 kN Cu.",
      "The internal clearance of 4T-323128 is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Order by the full 323128 code including suffixes — U, X, DX, E1 and UTG variants share the 140 mm bore but are different articles with different internal geometry.",
      "An unloaded 4T-323128 near 1,200 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 435/650 kN ratings and 66 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323128; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323128?",
        "a": "4T-323128 is a double-row tapered roller bearing of TDO (back-to-back) construction: 140 mm bore, 225 mm outside diameter and 68 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 435 kN, C0 650 kN, Cu 66 kN, grease limiting speed 1,200 r/min, oil speed 1,700 r/min, mass about 9.82 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 140 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323128 belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323128 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 68 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323128 mean?",
        "a": "With no letter suffix, 323128 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-323128 list two speeds, 1,200 and 1,700 r/min?",
        "a": "The lower figure, 1,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323128 at 1,700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323128",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-323128",
      "323128",
      "4T-323128"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413128",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413128",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 140,
    "D_mm": 225,
    "B_mm": 68,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 410,
    "static_load_kN": 580,
    "fatigue_load_limit_kN": 59,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1700,
    "weight_g": 9290,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-413128 denotes the light-duty 430-family TDO double-row series — a 140 mm bore double-row tapered unit rated 410 kN basic dynamic and 580 kN static. With no letter suffix, 413128 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code. Speed planning uses both catalogue columns: grease 1,200 r/min is the mechanical ceiling, oil 1,700 r/min with oil lubrication — a 500 r/min margin at this size. Because the unit is preset, mounting 4T-413128 resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Mount 4T-413128 as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 140 mm bore the 4T-413128 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 410 kN C level.",
      "The 430 light plan keeps 4T-413128 narrower and faster than the 432 heavy execution of the same 140 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Order by the full 413128 code including suffixes — U, X, DX, E1 and UTG variants share the 140 mm bore but are different articles with different internal geometry.",
      "An unloaded 4T-413128 near 1,200 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The internal clearance of 4T-413128 is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 410/580 kN ratings and 59 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413128; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413128?",
        "a": "4T-413128 is a double-row tapered roller bearing of TDO (back-to-back) construction: 140 mm bore, 225 mm outside diameter and 68 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 410 kN, C0 580 kN, Cu 59 kN, grease limiting speed 1,200 r/min, oil speed 1,700 r/min, mass about 9.29 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 140 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413128 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413128 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 68 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413128 mean?",
        "a": "With no letter suffix, 413128 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-413128 list two speeds, 1,200 and 1,700 r/min?",
        "a": "The lower figure, 1,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413128 at 1,700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413128",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-413128",
      "413128",
      "4T-413128"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423128",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423128",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 140,
    "D_mm": 225,
    "B_mm": 84,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 435,
    "static_load_kN": 650,
    "fatigue_load_limit_kN": 66,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1700,
    "weight_g": 11100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423128 is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 140×225×84 mm. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 140 mm bore the 432 execution carries a wider, heavier section than the 430. The fatigue load limit Cu printed for 4T-423128 is 66 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-423128 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 140 mm shaft. Induction heating to max 120 °C is the standard fitting method at this 140 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 140 mm bore the 4T-423128 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 435 kN C level.",
      "The 430 light plan keeps 4T-423128 narrower and faster than the 432 heavy execution of the same 140 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 225 mm OD clamping uniformly around the circumference.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 225 mm OD clamping uniformly around the circumference.",
      "Open 4T-423128 units have no seals: the housing must seal both rows or the 1,200 r/min grease figure is meaningless once contamination enters.",
      "The 435/650 kN ratings and 66 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423128; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423128?",
        "a": "4T-423128 is a double-row tapered roller bearing of TDO (back-to-back) construction: 140 mm bore, 225 mm outside diameter and 84 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 435 kN, C0 650 kN, Cu 66 kN, grease limiting speed 1,200 r/min, oil speed 1,700 r/min, mass about 11.1 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 140 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423128 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423128 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 84 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423128 mean?",
        "a": "With no letter suffix, 423128 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-423128 list two speeds, 1,200 and 1,700 r/min?",
        "a": "The lower figure, 1,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423128 at 1,700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423128",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-423128",
      "423128",
      "4T-423128"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430228XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430228XU",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 140,
    "D_mm": 250,
    "B_mm": 102,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 800,
    "static_load_kN": 1140,
    "fatigue_load_limit_kN": 114,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1600,
    "weight_g": 19200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430228XU is the NTN 4T catalogue entry for a 140×250×102 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Reading the designation: the last two digits 28 are the bore code, ×5 = 140 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. The 5.7 kN of dynamic capacity per millimetre of bore summarises the 800 kN rating over the 140 mm bore — compare substitution candidates on this ratio and on the 102 mm width. Because the unit is preset, mounting 4T-430228XU resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-430228XU's locating position.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 140 mm bore the 4T-430228XU unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 800 kN C level.",
      "The 430 light plan keeps 4T-430228XU narrower and faster than the 432 heavy execution of the same 140 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 55.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-430228XU or the cones bottom out on the radius.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 250 mm OD clamping uniformly around the circumference.",
      "Grease packs must leave free volume across the 102 mm width; over-greasing a unit churning near the 1,600 r/min oil-band speed raises temperature and expels the grease.",
      "The 800/1140 kN ratings and 114 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430228XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430228XU?",
        "a": "4T-430228XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 140 mm bore, 250 mm outside diameter and 102 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 800 kN, C0 1140 kN, Cu 114 kN, grease limiting speed 1,200 r/min, oil speed 1,600 r/min, mass about 19.2 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 140 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430228XU belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430228XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 102 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430228XU mean?",
        "a": "Suffix reading on 430228XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430228XU list two speeds, 1,200 and 1,600 r/min?",
        "a": "The lower figure, 1,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430228XU at 1,600 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430228XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430228xu",
      "4t-430228xu",
      "430228XU",
      "4T-430228XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432228XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432228XU",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 140,
    "D_mm": 250,
    "B_mm": 153,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1160,
    "static_load_kN": 1840,
    "fatigue_load_limit_kN": 184,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1600,
    "weight_g": 30000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-432228XU denotes the heavy-duty 432-family TDO double-row series — a 140 mm bore double-row tapered unit rated 1160 kN basic dynamic and 1840 kN static. Reading the designation: the last two digits 28 are the bore code, ×5 = 140 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. Catalogue mass of 4T-432228XU is 30 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. Because the unit is preset, mounting 4T-432228XU resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Mount 4T-432228XU as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 140 mm bore the 4T-432228XU unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1160 kN C level.",
      "The 432 heavy plan gives 4T-432228XU its 153 mm width and 1160 kN rating at the 140 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 184 kN Cu.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-432228XU feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-432228XU feeds the two roller complements evenly; a single-side feed starves the far row.",
      "At inspection do not mix the cone assemblies of 4T-432228XU with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 1160/1840 kN ratings and 184 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432228XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432228XU?",
        "a": "4T-432228XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 140 mm bore, 250 mm outside diameter and 153 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1160 kN, C0 1840 kN, Cu 184 kN, grease limiting speed 1,200 r/min, oil speed 1,600 r/min, mass about 30 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 140 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432228XU belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432228XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 153 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432228XU mean?",
        "a": "Suffix reading on 432228XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432228XU list two speeds, 1,200 and 1,600 r/min?",
        "a": "The lower figure, 1,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432228XU at 1,600 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432228XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432228xu",
      "4t-432228xu",
      "432228XU",
      "4T-432228XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430328X",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430328X",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 140,
    "D_mm": 300,
    "B_mm": 145,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1220,
    "static_load_kN": 1560,
    "fatigue_load_limit_kN": 150,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1400,
    "weight_g": 43200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-430328X at 140 mm bore, 300 mm OD and 145 mm overall width, with a grease limiting speed of 1,100 r/min and an oil ceiling of 1,400 r/min. Reading the designation: the last two digits 28 are the bore code, ×5 = 140 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. Catalogue mass of 4T-430328X is 43.2 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. TDO construction means the two cone assemblies of 4T-430328X face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 140 mm shaft. The open unit carries no seals; the housing of 4T-430328X must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 140 mm bore the 4T-430328X unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1220 kN C level.",
      "The 430 light plan keeps 4T-430328X narrower and faster than the 432 heavy execution of the same 140 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-430328X feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 300 mm OD clamping uniformly around the circumference.",
      "At inspection do not mix the cone assemblies of 4T-430328X with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 1220/1560 kN ratings and 150 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430328X; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430328X?",
        "a": "4T-430328X is a double-row tapered roller bearing of TDO (back-to-back) construction: 140 mm bore, 300 mm outside diameter and 145 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1220 kN, C0 1560 kN, Cu 150 kN, grease limiting speed 1,100 r/min, oil speed 1,400 r/min, mass about 43.2 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 140 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430328X belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430328X be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 145 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430328X mean?",
        "a": "Suffix reading on 430328X: X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430328X list two speeds, 1,100 and 1,400 r/min?",
        "a": "The lower figure, 1,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430328X at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430328X",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430328x",
      "4t-430328x",
      "430328X",
      "4T-430328X"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430328XUUTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430328XUUTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 140,
    "D_mm": 300,
    "B_mm": 145,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1620,
    "static_load_kN": 1900,
    "fatigue_load_limit_kN": 183,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1500,
    "weight_g": 45300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 140 mm shaft needing a compact two-direction thrust location, NTN lists 4T-430328XUUTG, a TDO double-row 4T unit of 1620 kN C and 1900 kN C0 in the light-duty 430-family TDO double-row series. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 430328XUUTG reads accordingly. Double-row capacity is not twice a single-row bearing: the printed 1620 kN C already accounts for load sharing between the two rows of 4T-430328XUUTG, so apply it directly in the L10 calculation. The internal clearance of 4T-430328XUUTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 145 mm overall width is the finished dimension. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-430328XUUTG.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 140 mm bore the 4T-430328XUUTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1620 kN C level.",
      "The 430 light plan keeps 4T-430328XUUTG narrower and faster than the 432 heavy execution of the same 140 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 145 mm width, load spread and clearance logic of 4T-430328XUUTG are unit-specific.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 300 mm OD clamping uniformly around the circumference.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-430328XUUTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 1620/1900 kN ratings and 183 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430328XUUTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430328XUUTG?",
        "a": "4T-430328XUUTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 140 mm bore, 300 mm outside diameter and 145 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1620 kN, C0 1900 kN, Cu 183 kN, grease limiting speed 1,100 r/min, oil speed 1,500 r/min, mass about 45.3 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 140 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430328XUUTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430328XUUTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 145 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430328XUUTG mean?",
        "a": "Suffix reading on 430328XUUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430328XUUTG list two speeds, 1,100 and 1,500 r/min?",
        "a": "The lower figure, 1,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430328XUUTG at 1,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430328XUUTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430328xuutg",
      "4t-430328xuutg",
      "＊430328xuutg",
      "430328XUUTG",
      "4T-430328XUUTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432328UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432328UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 140,
    "D_mm": 300,
    "B_mm": 223,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2170,
    "static_load_kN": 2740,
    "fatigue_load_limit_kN": 264,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1500,
    "weight_g": 68900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 140 mm shaft position as 4T-432328UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 223 mm. Suffix reading on 432328UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Double-row capacity is not twice a single-row bearing: the printed 2170 kN C already accounts for load sharing between the two rows of 4T-432328UTG, so apply it directly in the L10 calculation. The internal clearance of 4T-432328UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 223 mm overall width is the finished dimension. Axial clamping of the double cup must be uniform around the 300 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 140 mm bore the 4T-432328UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2170 kN C level.",
      "The 432 heavy plan gives 4T-432328UTG its 223 mm width and 2170 kN rating at the 140 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 264 kN Cu.",
      "The 80.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-432328UTG or the cones bottom out on the radius.",
      "An unloaded 4T-432328UTG near 1,100 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Grease packs must leave free volume across the 223 mm width; over-greasing a unit churning near the 1,500 r/min oil-band speed raises temperature and expels the grease.",
      "The 2170/2740 kN ratings and 264 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432328UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432328UTG?",
        "a": "4T-432328UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 140 mm bore, 300 mm outside diameter and 223 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2170 kN, C0 2740 kN, Cu 264 kN, grease limiting speed 1,100 r/min, oil speed 1,500 r/min, mass about 68.9 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 140 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432328UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432328UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 223 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432328UTG mean?",
        "a": "Suffix reading on 432328UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432328UTG list two speeds, 1,100 and 1,500 r/min?",
        "a": "The lower figure, 1,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432328UTG at 1,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432328UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432328utg",
      "4t-432328utg",
      "＊432328utg",
      "432328UTG",
      "4T-432328UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323030",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323030",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 150,
    "D_mm": 225,
    "B_mm": 56,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 395,
    "static_load_kN": 630,
    "fatigue_load_limit_kN": 64,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1600,
    "weight_g": 7630,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 150 mm shaft position as 4T-323030: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 56 mm. Reading the designation: the last two digits 30 are the bore code, ×5 = 150 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. Grease relubrication at the 1,200 r/min limiting speed must reach both roller rows; sustaining 1,600 r/min needs an oil supply with defined flow through the double cup. TDO construction means the two cone assemblies of 4T-323030 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 150 mm shaft. Mount 4T-323030 as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 150 mm bore the 4T-323030 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 395 kN C level.",
      "The 432 heavy plan gives 4T-323030 its 56 mm width and 395 kN rating at the 150 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 64 kN Cu.",
      "An unloaded 4T-323030 near 1,200 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 56 mm width, load spread and clearance logic of 4T-323030 are unit-specific.",
      "Order by the full 323030 code including suffixes — U, X, DX, E1 and UTG variants share the 150 mm bore but are different articles with different internal geometry.",
      "The 395/630 kN ratings and 64 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323030; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323030?",
        "a": "4T-323030 is a double-row tapered roller bearing of TDO (back-to-back) construction: 150 mm bore, 225 mm outside diameter and 56 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 395 kN, C0 630 kN, Cu 64 kN, grease limiting speed 1,200 r/min, oil speed 1,600 r/min, mass about 7.63 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 150 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323030 belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323030 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 56 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323030 mean?",
        "a": "With no letter suffix, 323030 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-323030 list two speeds, 1,200 and 1,600 r/min?",
        "a": "The lower figure, 1,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323030 at 1,600 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323030",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-323030",
      "323030",
      "4T-323030"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413030",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413030",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 150,
    "D_mm": 225,
    "B_mm": 56,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 305,
    "static_load_kN": 430,
    "fatigue_load_limit_kN": 43.5,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1600,
    "weight_g": 6660,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-413030 denotes the light-duty 430-family TDO double-row series — a 150 mm bore double-row tapered unit rated 305 kN basic dynamic and 430 kN static. With no letter suffix, 413030 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code. Double-row capacity is not twice a single-row bearing: the printed 305 kN C already accounts for load sharing between the two rows of 4T-413030, so apply it directly in the L10 calculation. Because the unit is preset, mounting 4T-413030 resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Mount 4T-413030 as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 150 mm bore the 4T-413030 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 305 kN C level.",
      "The 430 light plan keeps 4T-413030 narrower and faster than the 432 heavy execution of the same 150 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 305 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Grease packs must leave free volume across the 56 mm width; over-greasing a unit churning near the 1,600 r/min oil-band speed raises temperature and expels the grease.",
      "Open 4T-413030 units have no seals: the housing must seal both rows or the 1,200 r/min grease figure is meaningless once contamination enters.",
      "The 305/430 kN ratings and 43.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413030; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413030?",
        "a": "4T-413030 is a double-row tapered roller bearing of TDO (back-to-back) construction: 150 mm bore, 225 mm outside diameter and 56 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 305 kN, C0 430 kN, Cu 43.5 kN, grease limiting speed 1,200 r/min, oil speed 1,600 r/min, mass about 6.66 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 150 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413030 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413030 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 56 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413030 mean?",
        "a": "With no letter suffix, 413030 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-413030 list two speeds, 1,200 and 1,600 r/min?",
        "a": "The lower figure, 1,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413030 at 1,600 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413030",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-413030",
      "413030",
      "4T-413030"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423030",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423030",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 150,
    "D_mm": 225,
    "B_mm": 70,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 395,
    "static_load_kN": 630,
    "fatigue_load_limit_kN": 64,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1600,
    "weight_g": 8480,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423030 is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 150×225×70 mm. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 150 mm bore the 432 execution carries a wider, heavier section than the 430. The 2.6 kN of dynamic capacity per millimetre of bore summarises the 395 kN rating over the 150 mm bore — compare substitution candidates on this ratio and on the 70 mm width. TDO construction means the two cone assemblies of 4T-423030 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 150 mm shaft. Induction heating to max 120 °C is the standard fitting method at this 150 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 150 mm bore the 4T-423030 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 395 kN C level.",
      "The 430 light plan keeps 4T-423030 narrower and faster than the 432 heavy execution of the same 150 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Grease packs must leave free volume across the 70 mm width; over-greasing a unit churning near the 1,600 r/min oil-band speed raises temperature and expels the grease.",
      "At inspection do not mix the cone assemblies of 4T-423030 with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 225 mm OD clamping uniformly around the circumference.",
      "The 395/630 kN ratings and 64 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423030; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423030?",
        "a": "4T-423030 is a double-row tapered roller bearing of TDO (back-to-back) construction: 150 mm bore, 225 mm outside diameter and 70 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 395 kN, C0 630 kN, Cu 64 kN, grease limiting speed 1,200 r/min, oil speed 1,600 r/min, mass about 8.48 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 150 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423030 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423030 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 70 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423030 mean?",
        "a": "With no letter suffix, 423030 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-423030 list two speeds, 1,200 and 1,600 r/min?",
        "a": "The lower figure, 1,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423030 at 1,600 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423030",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-423030",
      "423030",
      "4T-423030"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323130",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323130",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 150,
    "D_mm": 250,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 670,
    "static_load_kN": 1040,
    "fatigue_load_limit_kN": 103,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1500,
    "weight_g": 15700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-323130 at 150 mm bore, 250 mm OD and 80 mm overall width, with a grease limiting speed of 1,200 r/min and an oil ceiling of 1,500 r/min. With no letter suffix, 323130 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code. Selection: C 670 kN against C0 1040 kN gives a C0/C ratio of 1.55; the two rows of 4T-323130 share the combined load as one bearing position. TDO construction means the two cone assemblies of 4T-323130 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 150 mm shaft. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-323130; the double cup must seat square across its full 80 mm width.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 150 mm bore the 4T-323130 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 670 kN C level.",
      "The 432 heavy plan gives 4T-323130 its 80 mm width and 670 kN rating at the 150 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 103 kN Cu.",
      "Open 4T-323130 units have no seals: the housing must seal both rows or the 1,200 r/min grease figure is meaningless once contamination enters.",
      "Open 4T-323130 units have no seals: the housing must seal both rows or the 1,200 r/min grease figure is meaningless once contamination enters.",
      "The internal clearance of 4T-323130 is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 670/1040 kN ratings and 103 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323130; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323130?",
        "a": "4T-323130 is a double-row tapered roller bearing of TDO (back-to-back) construction: 150 mm bore, 250 mm outside diameter and 80 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 670 kN, C0 1040 kN, Cu 103 kN, grease limiting speed 1,200 r/min, oil speed 1,500 r/min, mass about 15.7 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 150 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323130 belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323130 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 80 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323130 mean?",
        "a": "With no letter suffix, 323130 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-323130 list two speeds, 1,200 and 1,500 r/min?",
        "a": "The lower figure, 1,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323130 at 1,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323130",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-323130",
      "323130",
      "4T-323130"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413130",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413130",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 150,
    "D_mm": 250,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 540,
    "static_load_kN": 805,
    "fatigue_load_limit_kN": 79.5,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1500,
    "weight_g": 14600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413130 is the NTN 4T catalogue entry for a 150×250×80 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Unlike a pair of single-row bearings, the TDO unit of 4T-413130 integrates both rows in one article: the 80 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The fatigue load limit Cu printed for 4T-413130 is 79.5 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. Because the unit is preset, mounting 4T-413130 resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-413130; the double cup must seat square across its full 80 mm width.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 150 mm bore the 4T-413130 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 540 kN C level.",
      "The 430 light plan keeps 4T-413130 narrower and faster than the 432 heavy execution of the same 150 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-413130 feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The internal clearance of 4T-413130 is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 80 mm width, load spread and clearance logic of 4T-413130 are unit-specific.",
      "The 540/805 kN ratings and 79.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413130; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413130?",
        "a": "4T-413130 is a double-row tapered roller bearing of TDO (back-to-back) construction: 150 mm bore, 250 mm outside diameter and 80 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 540 kN, C0 805 kN, Cu 79.5 kN, grease limiting speed 1,200 r/min, oil speed 1,500 r/min, mass about 14.6 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 150 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413130 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413130 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 80 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413130 mean?",
        "a": "With no letter suffix, 413130 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-413130 list two speeds, 1,200 and 1,500 r/min?",
        "a": "The lower figure, 1,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413130 at 1,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413130",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-413130",
      "413130",
      "4T-413130"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423130",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423130",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 150,
    "D_mm": 250,
    "B_mm": 100,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 670,
    "static_load_kN": 1040,
    "fatigue_load_limit_kN": 103,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1500,
    "weight_g": 17600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 150 mm shaft position as 4T-423130: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 100 mm. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 423130 reads accordingly. Selection: C 670 kN against C0 1040 kN gives a C0/C ratio of 1.55; the two rows of 4T-423130 share the combined load as one bearing position. TDO construction means the two cone assemblies of 4T-423130 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 150 mm shaft. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-423130's locating position.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 150 mm bore the 4T-423130 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 670 kN C level.",
      "The 430 light plan keeps 4T-423130 narrower and faster than the 432 heavy execution of the same 150 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-423130 near 1,200 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 50.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-423130 or the cones bottom out on the radius.",
      "The 670 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 670/1040 kN ratings and 103 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423130; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423130?",
        "a": "4T-423130 is a double-row tapered roller bearing of TDO (back-to-back) construction: 150 mm bore, 250 mm outside diameter and 100 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 670 kN, C0 1040 kN, Cu 103 kN, grease limiting speed 1,200 r/min, oil speed 1,500 r/min, mass about 17.6 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 150 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423130 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423130 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 100 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423130 mean?",
        "a": "With no letter suffix, 423130 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-423130 list two speeds, 1,200 and 1,500 r/min?",
        "a": "The lower figure, 1,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423130 at 1,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423130",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=196",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-423130",
      "423130",
      "4T-423130"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430230U",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430230U",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 150,
    "D_mm": 270,
    "B_mm": 109,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 855,
    "static_load_kN": 1210,
    "fatigue_load_limit_kN": 118,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1500,
    "weight_g": 24100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 150 mm shaft position as 4T-430230U: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 109 mm. Suffix reading on 430230U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles. The 60.0 mm radial section over the 150 mm bore carries two roller rows across the 109 mm width; abutment shoulders must clear both cone bores and the double-cup OD. The internal clearance of 4T-430230U is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 109 mm overall width is the finished dimension. Induction heating to max 120 °C is the standard fitting method at this 150 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 150 mm bore the 4T-430230U unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 855 kN C level.",
      "The 430 light plan keeps 4T-430230U narrower and faster than the 432 heavy execution of the same 150 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-430230U near 1,100 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-430230U feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 60.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-430230U or the cones bottom out on the radius.",
      "The 855/1210 kN ratings and 118 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430230U; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430230U?",
        "a": "4T-430230U is a double-row tapered roller bearing of TDO (back-to-back) construction: 150 mm bore, 270 mm outside diameter and 109 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 855 kN, C0 1210 kN, Cu 118 kN, grease limiting speed 1,100 r/min, oil speed 1,500 r/min, mass about 24.1 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 150 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430230U belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430230U be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 109 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430230U mean?",
        "a": "Suffix reading on 430230U: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430230U list two speeds, 1,100 and 1,500 r/min?",
        "a": "The lower figure, 1,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430230U at 1,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430230U",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430230u",
      "4t-430230u",
      "430230U",
      "4T-430230U"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432230XU",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432230XU",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 150,
    "D_mm": 270,
    "B_mm": 164,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1330,
    "static_load_kN": 2140,
    "fatigue_load_limit_kN": 209,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1500,
    "weight_g": 38000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 150 mm shaft position as 4T-432230XU: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 164 mm. Reading the designation: the last two digits 30 are the bore code, ×5 = 150 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. Selection: C 1330 kN against C0 2140 kN gives a C0/C ratio of 1.61; the two rows of 4T-432230XU share the combined load as one bearing position. TDO construction means the two cone assemblies of 4T-432230XU face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 150 mm shaft. At 1330 kN C the unit offers about 8.9 kN per millimetre of the 150 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 1,500 r/min.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 150 mm bore the 4T-432230XU unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1330 kN C level.",
      "The 432 heavy plan gives 4T-432230XU its 164 mm width and 1330 kN rating at the 150 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 209 kN Cu.",
      "Order by the full 432230XU code including suffixes — U, X, DX, E1 and UTG variants share the 150 mm bore but are different articles with different internal geometry.",
      "Order by the full 432230XU code including suffixes — U, X, DX, E1 and UTG variants share the 150 mm bore but are different articles with different internal geometry.",
      "Order by the full 432230XU code including suffixes — U, X, DX, E1 and UTG variants share the 150 mm bore but are different articles with different internal geometry.",
      "The 1330/2140 kN ratings and 209 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432230XU; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432230XU?",
        "a": "4T-432230XU is a double-row tapered roller bearing of TDO (back-to-back) construction: 150 mm bore, 270 mm outside diameter and 164 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1330 kN, C0 2140 kN, Cu 209 kN, grease limiting speed 1,100 r/min, oil speed 1,500 r/min, mass about 38 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 150 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432230XU belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432230XU be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 164 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432230XU mean?",
        "a": "Suffix reading on 432230XU: U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432230XU list two speeds, 1,100 and 1,500 r/min?",
        "a": "The lower figure, 1,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432230XU at 1,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432230XU",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432230xu",
      "4t-432230xu",
      "432230XU",
      "4T-432230XU"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430330UUTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430330UUTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 150,
    "D_mm": 320,
    "B_mm": 154,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1810,
    "static_load_kN": 2140,
    "fatigue_load_limit_kN": 201,
    "limiting_speed_rpm": 990,
    "max_rpm": 990,
    "speed_oil_rpm": 1400,
    "weight_g": 54600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430330UUTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 150×320×154 mm. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 430330UUTG reads accordingly. The 12.1 kN of dynamic capacity per millimetre of bore summarises the 1810 kN rating over the 150 mm bore — compare substitution candidates on this ratio and on the 154 mm width. The internal clearance of 4T-430330UUTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 154 mm overall width is the finished dimension. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 150 mm size before ordering 4T-430330UUTG.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 150 mm bore the 4T-430330UUTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1810 kN C level.",
      "The 430 light plan keeps 4T-430330UUTG narrower and faster than the 432 heavy execution of the same 150 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 85.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-430330UUTG or the cones bottom out on the radius.",
      "An unloaded 4T-430330UUTG near 990 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "An unloaded 4T-430330UUTG near 990 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 1810/2140 kN ratings and 201 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430330UUTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430330UUTG?",
        "a": "4T-430330UUTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 150 mm bore, 320 mm outside diameter and 154 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1810 kN, C0 2140 kN, Cu 201 kN, grease limiting speed 990 r/min, oil speed 1,400 r/min, mass about 54.6 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 150 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430330UUTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430330UUTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 154 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430330UUTG mean?",
        "a": "Suffix reading on 430330UUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430330UUTG list two speeds, 990 and 1,400 r/min?",
        "a": "The lower figure, 990 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430330UUTG at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430330UUTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430330uutg",
      "4t-430330uutg",
      "＊430330uutg",
      "430330UUTG",
      "4T-430330UUTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323032",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323032",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 160,
    "D_mm": 240,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 475,
    "static_load_kN": 765,
    "fatigue_load_limit_kN": 76,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1500,
    "weight_g": 9420,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-323032 at 160 mm bore, 240 mm OD and 60 mm overall width, with a grease limiting speed of 1,100 r/min and an oil ceiling of 1,500 r/min. With no letter suffix, 323032 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code. The 40.0 mm radial section over the 160 mm bore carries two roller rows across the 60 mm width; abutment shoulders must clear both cone bores and the double-cup OD. TDO construction means the two cone assemblies of 4T-323032 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 160 mm shaft. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-323032's locating position.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 160 mm bore the 4T-323032 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 475 kN C level.",
      "The 432 heavy plan gives 4T-323032 its 60 mm width and 475 kN rating at the 160 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 76 kN Cu.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 60 mm width, load spread and clearance logic of 4T-323032 are unit-specific.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-323032 feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-323032 feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 475/765 kN ratings and 76 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323032; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323032?",
        "a": "4T-323032 is a double-row tapered roller bearing of TDO (back-to-back) construction: 160 mm bore, 240 mm outside diameter and 60 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 475 kN, C0 765 kN, Cu 76 kN, grease limiting speed 1,100 r/min, oil speed 1,500 r/min, mass about 9.42 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 160 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323032 belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323032 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 60 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323032 mean?",
        "a": "With no letter suffix, 323032 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-323032 list two speeds, 1,100 and 1,500 r/min?",
        "a": "The lower figure, 1,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323032 at 1,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323032",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-323032",
      "323032",
      "4T-323032"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413032",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413032",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 160,
    "D_mm": 240,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 370,
    "static_load_kN": 535,
    "fatigue_load_limit_kN": 53,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1500,
    "weight_g": 8390,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413032 is the NTN 4T catalogue entry for a 160×240×60 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 160 mm bore the 432 execution carries a wider, heavier section than the 430. Speed planning uses both catalogue columns: grease 1,100 r/min is the mechanical ceiling, oil 1,500 r/min with oil lubrication — a 400 r/min margin at this size. Because the unit is preset, mounting 4T-413032 resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-413032's locating position.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 160 mm bore the 4T-413032 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 370 kN C level.",
      "The 430 light plan keeps 4T-413032 narrower and faster than the 432 heavy execution of the same 160 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-413032 near 1,100 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Order by the full 413032 code including suffixes — U, X, DX, E1 and UTG variants share the 160 mm bore but are different articles with different internal geometry.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 240 mm OD clamping uniformly around the circumference.",
      "The 370/535 kN ratings and 53 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413032; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413032?",
        "a": "4T-413032 is a double-row tapered roller bearing of TDO (back-to-back) construction: 160 mm bore, 240 mm outside diameter and 60 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 370 kN, C0 535 kN, Cu 53 kN, grease limiting speed 1,100 r/min, oil speed 1,500 r/min, mass about 8.39 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 160 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413032 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413032 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 60 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413032 mean?",
        "a": "With no letter suffix, 413032 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-413032 list two speeds, 1,100 and 1,500 r/min?",
        "a": "The lower figure, 1,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413032 at 1,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413032",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-413032",
      "413032",
      "4T-413032"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423032",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423032",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 160,
    "D_mm": 240,
    "B_mm": 75,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 475,
    "static_load_kN": 765,
    "fatigue_load_limit_kN": 76,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1500,
    "weight_g": 10700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 160 mm shaft position as 4T-423032: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 75 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-423032 integrates both rows in one article: the 75 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The fatigue load limit Cu printed for 4T-423032 is 76 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-423032 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 160 mm shaft. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 160 mm size before ordering 4T-423032.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 160 mm bore the 4T-423032 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 475 kN C level.",
      "The 430 light plan keeps 4T-423032 narrower and faster than the 432 heavy execution of the same 160 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Open 4T-423032 units have no seals: the housing must seal both rows or the 1,100 r/min grease figure is meaningless once contamination enters.",
      "An unloaded 4T-423032 near 1,100 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "An unloaded 4T-423032 near 1,100 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 475/765 kN ratings and 76 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423032; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423032?",
        "a": "4T-423032 is a double-row tapered roller bearing of TDO (back-to-back) construction: 160 mm bore, 240 mm outside diameter and 75 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 475 kN, C0 765 kN, Cu 76 kN, grease limiting speed 1,100 r/min, oil speed 1,500 r/min, mass about 10.7 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 160 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423032 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423032 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 75 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423032 mean?",
        "a": "With no letter suffix, 423032 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-423032 list two speeds, 1,100 and 1,500 r/min?",
        "a": "The lower figure, 1,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423032 at 1,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423032",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-423032",
      "423032",
      "4T-423032"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323132UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323132UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 160,
    "D_mm": 270,
    "B_mm": 86,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 865,
    "static_load_kN": 1180,
    "fatigue_load_limit_kN": 114,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1600,
    "weight_g": 20000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 160 mm shaft needing a compact two-direction thrust location, NTN lists 4T-323132UTG, a TDO double-row 4T unit of 865 kN C and 1180 kN C0 in the heavy-duty 432-family TDO double-row series. Suffix reading on 323132UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. The 5.4 kN of dynamic capacity per millimetre of bore summarises the 865 kN rating over the 160 mm bore — compare substitution candidates on this ratio and on the 86 mm width. TDO construction means the two cone assemblies of 4T-323132UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 160 mm shaft. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-323132UTG.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 160 mm bore the 4T-323132UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 865 kN C level.",
      "The 432 heavy plan gives 4T-323132UTG its 86 mm width and 865 kN rating at the 160 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 114 kN Cu.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 270 mm OD clamping uniformly around the circumference.",
      "Order by the full 323132UTG code including suffixes — U, X, DX, E1 and UTG variants share the 160 mm bore but are different articles with different internal geometry.",
      "The internal clearance of 4T-323132UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 865/1180 kN ratings and 114 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323132UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323132UTG?",
        "a": "4T-323132UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 160 mm bore, 270 mm outside diameter and 86 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 865 kN, C0 1180 kN, Cu 114 kN, grease limiting speed 1,100 r/min, oil speed 1,600 r/min, mass about 20 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 160 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323132UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323132UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 86 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323132UTG mean?",
        "a": "Suffix reading on 323132UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323132UTG list two speeds, 1,100 and 1,600 r/min?",
        "a": "The lower figure, 1,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323132UTG at 1,600 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323132UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323132utg",
      "4t-323132utg",
      "＊323132utg",
      "323132UTG",
      "4T-323132UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413132UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413132UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 160,
    "D_mm": 270,
    "B_mm": 86,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 760,
    "static_load_kN": 965,
    "fatigue_load_limit_kN": 93,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1600,
    "weight_g": 18200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 160 mm shaft needing a compact two-direction thrust location, NTN lists 4T-413132UTG, a TDO double-row 4T unit of 760 kN C and 965 kN C0 in the light-duty 430-family TDO double-row series. Unlike a pair of single-row bearings, the TDO unit of 4T-413132UTG integrates both rows in one article: the 86 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Grease relubrication at the 1,100 r/min limiting speed must reach both roller rows; sustaining 1,600 r/min needs an oil supply with defined flow through the double cup. Because the unit is preset, mounting 4T-413132UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Induction heating to max 120 °C is the standard fitting method at this 160 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 160 mm bore the 4T-413132UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 760 kN C level.",
      "The 430 light plan keeps 4T-413132UTG narrower and faster than the 432 heavy execution of the same 160 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-413132UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Open 4T-413132UTG units have no seals: the housing must seal both rows or the 1,100 r/min grease figure is meaningless once contamination enters.",
      "The 760 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 760/965 kN ratings and 93 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413132UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413132UTG?",
        "a": "4T-413132UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 160 mm bore, 270 mm outside diameter and 86 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 760 kN, C0 965 kN, Cu 93 kN, grease limiting speed 1,100 r/min, oil speed 1,600 r/min, mass about 18.2 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 160 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413132UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413132UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 86 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413132UTG mean?",
        "a": "Suffix reading on 413132UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413132UTG list two speeds, 1,100 and 1,600 r/min?",
        "a": "The lower figure, 1,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413132UTG at 1,600 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413132UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413132utg",
      "4t-413132utg",
      "＊413132utg",
      "413132UTG",
      "4T-413132UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423132UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423132UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 160,
    "D_mm": 270,
    "B_mm": 108,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 865,
    "static_load_kN": 1180,
    "fatigue_load_limit_kN": 114,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1600,
    "weight_g": 22500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423132UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 160×270×108 mm. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 423132UTG reads accordingly. The 5.4 kN of dynamic capacity per millimetre of bore summarises the 865 kN rating over the 160 mm bore — compare substitution candidates on this ratio and on the 108 mm width. The internal clearance of 4T-423132UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 108 mm overall width is the finished dimension. The open unit carries no seals; the housing of 4T-423132UTG must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 160 mm bore the 4T-423132UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 865 kN C level.",
      "The 430 light plan keeps 4T-423132UTG narrower and faster than the 432 heavy execution of the same 160 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 865 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 108 mm width, load spread and clearance logic of 4T-423132UTG are unit-specific.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 270 mm OD clamping uniformly around the circumference.",
      "The 865/1180 kN ratings and 114 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423132UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423132UTG?",
        "a": "4T-423132UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 160 mm bore, 270 mm outside diameter and 108 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 865 kN, C0 1180 kN, Cu 114 kN, grease limiting speed 1,100 r/min, oil speed 1,600 r/min, mass about 22.5 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 160 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423132UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423132UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 108 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423132UTG mean?",
        "a": "Suffix reading on 423132UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423132UTG list two speeds, 1,100 and 1,600 r/min?",
        "a": "The lower figure, 1,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423132UTG at 1,600 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423132UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423132utg",
      "4t-423132utg",
      "＊423132utg",
      "423132UTG",
      "4T-423132UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430232UUTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430232UUTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 160,
    "D_mm": 290,
    "B_mm": 115,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1150,
    "static_load_kN": 1440,
    "fatigue_load_limit_kN": 137,
    "limiting_speed_rpm": 1000,
    "max_rpm": 1000,
    "speed_oil_rpm": 1400,
    "weight_g": 29300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-430232UUTG denotes the light-duty 430-family TDO double-row series — a 160 mm bore double-row tapered unit rated 1150 kN basic dynamic and 1440 kN static. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 430232UUTG reads accordingly. The fatigue load limit Cu printed for 4T-430232UUTG is 137 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-430232UUTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 160 mm shaft. At 1150 kN C the unit offers about 7.2 kN per millimetre of the 160 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 1,400 r/min.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 160 mm bore the 4T-430232UUTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1150 kN C level.",
      "The 430 light plan keeps 4T-430232UUTG narrower and faster than the 432 heavy execution of the same 160 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Order by the full 430232UUTG code including suffixes — U, X, DX, E1 and UTG variants share the 160 mm bore but are different articles with different internal geometry.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 115 mm width, load spread and clearance logic of 4T-430232UUTG are unit-specific.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-430232UUTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 1150/1440 kN ratings and 137 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430232UUTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430232UUTG?",
        "a": "4T-430232UUTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 160 mm bore, 290 mm outside diameter and 115 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1150 kN, C0 1440 kN, Cu 137 kN, grease limiting speed 1,000 r/min, oil speed 1,400 r/min, mass about 29.3 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 160 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430232UUTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430232UUTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 115 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430232UUTG mean?",
        "a": "Suffix reading on 430232UUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430232UUTG list two speeds, 1,000 and 1,400 r/min?",
        "a": "The lower figure, 1,000 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430232UUTG at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430232UUTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430232uutg",
      "4t-430232uutg",
      "＊430232uutg",
      "430232UUTG",
      "4T-430232UUTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432232UUTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432232UUTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 160,
    "D_mm": 290,
    "B_mm": 178,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1960,
    "static_load_kN": 2840,
    "fatigue_load_limit_kN": 272,
    "limiting_speed_rpm": 1000,
    "max_rpm": 1000,
    "speed_oil_rpm": 1400,
    "weight_g": 49900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 160 mm shaft needing a compact two-direction thrust location, NTN lists 4T-432232UUTG, a TDO double-row 4T unit of 1960 kN C and 2840 kN C0 in the heavy-duty 432-family TDO double-row series. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 160 mm bore the 432 execution carries a wider, heavier section than the 430. Grease relubrication at the 1,000 r/min limiting speed must reach both roller rows; sustaining 1,400 r/min needs an oil supply with defined flow through the double cup. Because the unit is preset, mounting 4T-432232UUTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. At 1960 kN C the unit offers about 12.3 kN per millimetre of the 160 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 1,400 r/min.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 160 mm bore the 4T-432232UUTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1960 kN C level.",
      "The 432 heavy plan gives 4T-432232UUTG its 178 mm width and 1960 kN rating at the 160 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 272 kN Cu.",
      "The 65.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-432232UUTG or the cones bottom out on the radius.",
      "Order by the full 432232UUTG code including suffixes — U, X, DX, E1 and UTG variants share the 160 mm bore but are different articles with different internal geometry.",
      "Order by the full 432232UUTG code including suffixes — U, X, DX, E1 and UTG variants share the 160 mm bore but are different articles with different internal geometry.",
      "The 1960/2840 kN ratings and 272 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432232UUTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432232UUTG?",
        "a": "4T-432232UUTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 160 mm bore, 290 mm outside diameter and 178 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1960 kN, C0 2840 kN, Cu 272 kN, grease limiting speed 1,000 r/min, oil speed 1,400 r/min, mass about 49.9 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 160 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432232UUTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432232UUTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 178 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432232UUTG mean?",
        "a": "Suffix reading on 432232UUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432232UUTG list two speeds, 1,000 and 1,400 r/min?",
        "a": "The lower figure, 1,000 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432232UUTG at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432232UUTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432232uutg",
      "4t-432232uutg",
      "＊432232uutg",
      "432232UUTG",
      "4T-432232UUTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430332XUUTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430332XUUTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 160,
    "D_mm": 340,
    "B_mm": 160,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2010,
    "static_load_kN": 2390,
    "fatigue_load_limit_kN": 221,
    "limiting_speed_rpm": 920,
    "max_rpm": 920,
    "speed_oil_rpm": 1300,
    "weight_g": 63800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430332XUUTG is the NTN 4T catalogue entry for a 160×340×160 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Suffix reading on 430332XUUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles. The 90.0 mm radial section over the 160 mm bore carries two roller rows across the 160 mm width; abutment shoulders must clear both cone bores and the double-cup OD. The internal clearance of 4T-430332XUUTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 160 mm overall width is the finished dimension. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-430332XUUTG.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 160 mm bore the 4T-430332XUUTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2010 kN C level.",
      "The 430 light plan keeps 4T-430332XUUTG narrower and faster than the 432 heavy execution of the same 160 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-430332XUUTG near 920 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Order by the full 430332XUUTG code including suffixes — U, X, DX, E1 and UTG variants share the 160 mm bore but are different articles with different internal geometry.",
      "The internal clearance of 4T-430332XUUTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 2010/2390 kN ratings and 221 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430332XUUTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430332XUUTG?",
        "a": "4T-430332XUUTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 160 mm bore, 340 mm outside diameter and 160 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2010 kN, C0 2390 kN, Cu 221 kN, grease limiting speed 920 r/min, oil speed 1,300 r/min, mass about 63.8 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 160 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430332XUUTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430332XUUTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 160 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430332XUUTG mean?",
        "a": "Suffix reading on 430332XUUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430332XUUTG list two speeds, 920 and 1,300 r/min?",
        "a": "The lower figure, 920 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430332XUUTG at 1,300 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430332XUUTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430332xuutg",
      "4t-430332xuutg",
      "＊430332xuutg",
      "430332XUUTG",
      "4T-430332XUUTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323034E1",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323034E1",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 170,
    "D_mm": 260,
    "B_mm": 67,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 545,
    "static_load_kN": 865,
    "fatigue_load_limit_kN": 83.5,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1400,
    "weight_g": 12800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 170 mm shaft needing a compact two-direction thrust location, NTN lists 4T-323034E1, a TDO double-row 4T unit of 545 kN C and 865 kN C0 in the heavy-duty 432-family TDO double-row series. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 170 mm bore the 432 execution carries a wider, heavier section than the 430. Catalogue mass of 4T-323034E1 is 12.8 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. TDO construction means the two cone assemblies of 4T-323034E1 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 170 mm shaft. The open unit carries no seals; the housing of 4T-323034E1 must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 170 mm bore the 4T-323034E1 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 545 kN C level.",
      "The 432 heavy plan gives 4T-323034E1 its 67 mm width and 545 kN rating at the 170 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 83.5 kN Cu.",
      "The 545 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Grease packs must leave free volume across the 67 mm width; over-greasing a unit churning near the 1,400 r/min oil-band speed raises temperature and expels the grease.",
      "The 45.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-323034E1 or the cones bottom out on the radius.",
      "The 545/865 kN ratings and 83.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323034E1; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323034E1?",
        "a": "4T-323034E1 is a double-row tapered roller bearing of TDO (back-to-back) construction: 170 mm bore, 260 mm outside diameter and 67 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 545 kN, C0 865 kN, Cu 83.5 kN, grease limiting speed 1,100 r/min, oil speed 1,400 r/min, mass about 12.8 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 170 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323034E1 belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323034E1 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 67 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323034E1 mean?",
        "a": "Suffix reading on 323034E1: E1 is an internal-design revision of the base number, not a seal or clearance code; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323034E1 list two speeds, 1,100 and 1,400 r/min?",
        "a": "The lower figure, 1,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323034E1 at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323034E1",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323034e1",
      "4t-323034e1",
      "323034E1",
      "4T-323034E1"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413034",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413034",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 170,
    "D_mm": 260,
    "B_mm": 67,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 405,
    "static_load_kN": 620,
    "fatigue_load_limit_kN": 60,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1400,
    "weight_g": 11600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 170 mm shaft needing a compact two-direction thrust location, NTN lists 4T-413034, a TDO double-row 4T unit of 405 kN C and 620 kN C0 in the light-duty 430-family TDO double-row series. Unlike a pair of single-row bearings, the TDO unit of 4T-413034 integrates both rows in one article: the 67 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Grease relubrication at the 1,100 r/min limiting speed must reach both roller rows; sustaining 1,400 r/min needs an oil supply with defined flow through the double cup. Because the unit is preset, mounting 4T-413034 resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. The open unit carries no seals; the housing of 4T-413034 must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 170 mm bore the 4T-413034 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 405 kN C level.",
      "The 430 light plan keeps 4T-413034 narrower and faster than the 432 heavy execution of the same 170 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 67 mm width, load spread and clearance logic of 4T-413034 are unit-specific.",
      "Open 4T-413034 units have no seals: the housing must seal both rows or the 1,100 r/min grease figure is meaningless once contamination enters.",
      "An unloaded 4T-413034 near 1,100 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 405/620 kN ratings and 60 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413034; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413034?",
        "a": "4T-413034 is a double-row tapered roller bearing of TDO (back-to-back) construction: 170 mm bore, 260 mm outside diameter and 67 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 405 kN, C0 620 kN, Cu 60 kN, grease limiting speed 1,100 r/min, oil speed 1,400 r/min, mass about 11.6 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 170 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413034 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413034 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 67 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413034 mean?",
        "a": "With no letter suffix, 413034 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-413034 list two speeds, 1,100 and 1,400 r/min?",
        "a": "The lower figure, 1,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413034 at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413034",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-413034",
      "413034",
      "4T-413034"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423034",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423034",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 170,
    "D_mm": 260,
    "B_mm": 84,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 545,
    "static_load_kN": 865,
    "fatigue_load_limit_kN": 83.5,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1400,
    "weight_g": 14300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-423034 at 170 mm bore, 260 mm OD and 84 mm overall width, with a grease limiting speed of 1,100 r/min and an oil ceiling of 1,400 r/min. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 423034 reads accordingly. Double-row capacity is not twice a single-row bearing: the printed 545 kN C already accounts for load sharing between the two rows of 4T-423034, so apply it directly in the L10 calculation. TDO construction means the two cone assemblies of 4T-423034 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 170 mm shaft. With a rotating shaft a m6/n6 seat on the 170 mm journal and a located cup in the housing are typical practice for 4T-423034.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 170 mm bore the 4T-423034 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 545 kN C level.",
      "The 430 light plan keeps 4T-423034 narrower and faster than the 432 heavy execution of the same 170 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "At inspection do not mix the cone assemblies of 4T-423034 with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The internal clearance of 4T-423034 is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Order by the full 423034 code including suffixes — U, X, DX, E1 and UTG variants share the 170 mm bore but are different articles with different internal geometry.",
      "The 545/865 kN ratings and 83.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423034; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423034?",
        "a": "4T-423034 is a double-row tapered roller bearing of TDO (back-to-back) construction: 170 mm bore, 260 mm outside diameter and 84 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 545 kN, C0 865 kN, Cu 83.5 kN, grease limiting speed 1,100 r/min, oil speed 1,400 r/min, mass about 14.3 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 170 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423034 belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423034 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 84 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423034 mean?",
        "a": "With no letter suffix, 423034 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-423034 list two speeds, 1,100 and 1,400 r/min?",
        "a": "The lower figure, 1,100 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423034 at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423034",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-423034",
      "423034",
      "4T-423034"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323134UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323134UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 170,
    "D_mm": 280,
    "B_mm": 88,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 930,
    "static_load_kN": 1270,
    "fatigue_load_limit_kN": 122,
    "limiting_speed_rpm": 1000,
    "max_rpm": 1000,
    "speed_oil_rpm": 1500,
    "weight_g": 21800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-323134UTG denotes the heavy-duty 432-family TDO double-row series — a 170 mm bore double-row tapered unit rated 930 kN basic dynamic and 1270 kN static. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 323134UTG reads accordingly. The fatigue load limit Cu printed for 4T-323134UTG is 122 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. Because the unit is preset, mounting 4T-323134UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. With a rotating shaft a m6/n6 seat on the 170 mm journal and a located cup in the housing are typical practice for 4T-323134UTG.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 170 mm bore the 4T-323134UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 930 kN C level.",
      "The 432 heavy plan gives 4T-323134UTG its 88 mm width and 930 kN rating at the 170 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 122 kN Cu.",
      "The 55.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-323134UTG or the cones bottom out on the radius.",
      "At inspection do not mix the cone assemblies of 4T-323134UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The internal clearance of 4T-323134UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 930/1270 kN ratings and 122 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323134UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323134UTG?",
        "a": "4T-323134UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 170 mm bore, 280 mm outside diameter and 88 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 930 kN, C0 1270 kN, Cu 122 kN, grease limiting speed 1,000 r/min, oil speed 1,500 r/min, mass about 21.8 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 170 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323134UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323134UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 88 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323134UTG mean?",
        "a": "Suffix reading on 323134UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323134UTG list two speeds, 1,000 and 1,500 r/min?",
        "a": "The lower figure, 1,000 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323134UTG at 1,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323134UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323134utg",
      "4t-323134utg",
      "＊323134utg",
      "323134UTG",
      "4T-323134UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413134UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413134UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 170,
    "D_mm": 280,
    "B_mm": 88,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 705,
    "static_load_kN": 900,
    "fatigue_load_limit_kN": 86,
    "limiting_speed_rpm": 1000,
    "max_rpm": 1000,
    "speed_oil_rpm": 1500,
    "weight_g": 19200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-413134UTG denotes the light-duty 430-family TDO double-row series — a 170 mm bore double-row tapered unit rated 705 kN basic dynamic and 900 kN static. Suffix reading on 413134UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. The 55.0 mm radial section over the 170 mm bore carries two roller rows across the 88 mm width; abutment shoulders must clear both cone bores and the double-cup OD. The internal clearance of 4T-413134UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 88 mm overall width is the finished dimension. The open unit carries no seals; the housing of 4T-413134UTG must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 170 mm bore the 4T-413134UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 705 kN C level.",
      "The 430 light plan keeps 4T-413134UTG narrower and faster than the 432 heavy execution of the same 170 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 280 mm OD clamping uniformly around the circumference.",
      "An unloaded 4T-413134UTG near 1,000 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 705 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 705/900 kN ratings and 86 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413134UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413134UTG?",
        "a": "4T-413134UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 170 mm bore, 280 mm outside diameter and 88 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 705 kN, C0 900 kN, Cu 86 kN, grease limiting speed 1,000 r/min, oil speed 1,500 r/min, mass about 19.2 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 170 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413134UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413134UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 88 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413134UTG mean?",
        "a": "Suffix reading on 413134UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413134UTG list two speeds, 1,000 and 1,500 r/min?",
        "a": "The lower figure, 1,000 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413134UTG at 1,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413134UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413134utg",
      "4t-413134utg",
      "＊413134utg",
      "413134UTG",
      "4T-413134UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423134UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423134UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 170,
    "D_mm": 280,
    "B_mm": 110,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 930,
    "static_load_kN": 1270,
    "fatigue_load_limit_kN": 122,
    "limiting_speed_rpm": 1000,
    "max_rpm": 1000,
    "speed_oil_rpm": 1500,
    "weight_g": 24200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423134UTG is the NTN 4T catalogue entry for a 170×280×110 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 170 mm bore the 432 execution carries a wider, heavier section than the 430. The fatigue load limit Cu printed for 4T-423134UTG is 122 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-423134UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 170 mm shaft. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 170 mm size before ordering 4T-423134UTG.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 170 mm bore the 4T-423134UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 930 kN C level.",
      "The 430 light plan keeps 4T-423134UTG narrower and faster than the 432 heavy execution of the same 170 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "At inspection do not mix the cone assemblies of 4T-423134UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 55.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-423134UTG or the cones bottom out on the radius.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 280 mm OD clamping uniformly around the circumference.",
      "The 930/1270 kN ratings and 122 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423134UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423134UTG?",
        "a": "4T-423134UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 170 mm bore, 280 mm outside diameter and 110 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 930 kN, C0 1270 kN, Cu 122 kN, grease limiting speed 1,000 r/min, oil speed 1,500 r/min, mass about 24.2 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 170 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423134UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423134UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 110 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423134UTG mean?",
        "a": "Suffix reading on 423134UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423134UTG list two speeds, 1,000 and 1,500 r/min?",
        "a": "The lower figure, 1,000 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423134UTG at 1,500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423134UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423134utg",
      "4t-423134utg",
      "＊423134utg",
      "423134UTG",
      "4T-423134UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430234UUTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430234UUTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 170,
    "D_mm": 310,
    "B_mm": 125,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1340,
    "static_load_kN": 1690,
    "fatigue_load_limit_kN": 159,
    "limiting_speed_rpm": 950,
    "max_rpm": 950,
    "speed_oil_rpm": 1400,
    "weight_g": 37100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-430234UUTG denotes the light-duty 430-family TDO double-row series — a 170 mm bore double-row tapered unit rated 1340 kN basic dynamic and 1690 kN static. Suffix reading on 430234UUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles. Axial capacity is bidirectional because the rows are opposed: 4T-430234UUTG locates the shaft in both directions with C0 1690 kN behind the static check of the more heavily loaded row. TDO construction means the two cone assemblies of 4T-430234UUTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 170 mm shaft. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 170 mm size before ordering 4T-430234UUTG.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 170 mm bore the 4T-430234UUTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1340 kN C level.",
      "The 430 light plan keeps 4T-430234UUTG narrower and faster than the 432 heavy execution of the same 170 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The internal clearance of 4T-430234UUTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "At inspection do not mix the cone assemblies of 4T-430234UUTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Open 4T-430234UUTG units have no seals: the housing must seal both rows or the 950 r/min grease figure is meaningless once contamination enters.",
      "The 1340/1690 kN ratings and 159 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430234UUTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430234UUTG?",
        "a": "4T-430234UUTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 170 mm bore, 310 mm outside diameter and 125 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1340 kN, C0 1690 kN, Cu 159 kN, grease limiting speed 950 r/min, oil speed 1,400 r/min, mass about 37.1 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 170 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430234UUTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430234UUTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 125 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430234UUTG mean?",
        "a": "Suffix reading on 430234UUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430234UUTG list two speeds, 950 and 1,400 r/min?",
        "a": "The lower figure, 950 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430234UUTG at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430234UUTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430234uutg",
      "4t-430234uutg",
      "＊430234uutg",
      "430234UUTG",
      "4T-430234UUTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432234XUUTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432234XUUTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 170,
    "D_mm": 310,
    "B_mm": 192,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2190,
    "static_load_kN": 3200,
    "fatigue_load_limit_kN": 300,
    "limiting_speed_rpm": 950,
    "max_rpm": 950,
    "speed_oil_rpm": 1400,
    "weight_g": 61300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-432234XUUTG is the NTN 4T catalogue entry for a 170×310×192 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Suffix reading on 432234XUUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles. Catalogue mass of 4T-432234XUUTG is 61.3 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. The internal clearance of 4T-432234XUUTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 192 mm overall width is the finished dimension. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-432234XUUTG; the double cup must seat square across its full 192 mm width.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 170 mm bore the 4T-432234XUUTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2190 kN C level.",
      "The 432 heavy plan gives 4T-432234XUUTG its 192 mm width and 2190 kN rating at the 170 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 300 kN Cu.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 192 mm width, load spread and clearance logic of 4T-432234XUUTG are unit-specific.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 192 mm width, load spread and clearance logic of 4T-432234XUUTG are unit-specific.",
      "The 70.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-432234XUUTG or the cones bottom out on the radius.",
      "The 2190/3200 kN ratings and 300 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432234XUUTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432234XUUTG?",
        "a": "4T-432234XUUTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 170 mm bore, 310 mm outside diameter and 192 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2190 kN, C0 3200 kN, Cu 300 kN, grease limiting speed 950 r/min, oil speed 1,400 r/min, mass about 61.3 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 170 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432234XUUTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432234XUUTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 192 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432234XUUTG mean?",
        "a": "Suffix reading on 432234XUUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432234XUUTG list two speeds, 950 and 1,400 r/min?",
        "a": "The lower figure, 950 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432234XUUTG at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432234XUUTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432234xuutg",
      "4t-432234xuutg",
      "＊432234xuutg",
      "432234XUUTG",
      "4T-432234XUUTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323036UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323036UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 180,
    "D_mm": 280,
    "B_mm": 74,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 745,
    "static_load_kN": 1050,
    "fatigue_load_limit_kN": 99.5,
    "limiting_speed_rpm": 1000,
    "max_rpm": 1000,
    "speed_oil_rpm": 1400,
    "weight_g": 16500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-323036UTG at 180 mm bore, 280 mm OD and 74 mm overall width, with a grease limiting speed of 1,000 r/min and an oil ceiling of 1,400 r/min. Reading the designation: the last two digits 36 are the bore code, ×5 = 180 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. Grease relubrication at the 1,000 r/min limiting speed must reach both roller rows; sustaining 1,400 r/min needs an oil supply with defined flow through the double cup. The internal clearance of 4T-323036UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 74 mm overall width is the finished dimension. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-323036UTG's locating position.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 180 mm bore the 4T-323036UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 745 kN C level.",
      "The 432 heavy plan gives 4T-323036UTG its 74 mm width and 745 kN rating at the 180 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 99.5 kN Cu.",
      "An unloaded 4T-323036UTG near 1,000 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "An unloaded 4T-323036UTG near 1,000 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 50.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-323036UTG or the cones bottom out on the radius.",
      "The 745/1050 kN ratings and 99.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323036UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323036UTG?",
        "a": "4T-323036UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 180 mm bore, 280 mm outside diameter and 74 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 745 kN, C0 1050 kN, Cu 99.5 kN, grease limiting speed 1,000 r/min, oil speed 1,400 r/min, mass about 16.5 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 180 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323036UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323036UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 74 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323036UTG mean?",
        "a": "Suffix reading on 323036UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323036UTG list two speeds, 1,000 and 1,400 r/min?",
        "a": "The lower figure, 1,000 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323036UTG at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323036UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323036utg",
      "4t-323036utg",
      "＊323036utg",
      "323036UTG",
      "4T-323036UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413036UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413036UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 180,
    "D_mm": 280,
    "B_mm": 74,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 545,
    "static_load_kN": 735,
    "fatigue_load_limit_kN": 69.5,
    "limiting_speed_rpm": 1000,
    "max_rpm": 1000,
    "speed_oil_rpm": 1400,
    "weight_g": 15200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-413036UTG at 180 mm bore, 280 mm OD and 74 mm overall width, with a grease limiting speed of 1,000 r/min and an oil ceiling of 1,400 r/min. Suffix reading on 413036UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Axial capacity is bidirectional because the rows are opposed: 4T-413036UTG locates the shaft in both directions with C0 735 kN behind the static check of the more heavily loaded row. Because the unit is preset, mounting 4T-413036UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-413036UTG are ground as a unit.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 180 mm bore the 4T-413036UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 545 kN C level.",
      "The 430 light plan keeps 4T-413036UTG narrower and faster than the 432 heavy execution of the same 180 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 74 mm width, load spread and clearance logic of 4T-413036UTG are unit-specific.",
      "Grease packs must leave free volume across the 74 mm width; over-greasing a unit churning near the 1,400 r/min oil-band speed raises temperature and expels the grease.",
      "At inspection do not mix the cone assemblies of 4T-413036UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 545/735 kN ratings and 69.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413036UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413036UTG?",
        "a": "4T-413036UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 180 mm bore, 280 mm outside diameter and 74 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 545 kN, C0 735 kN, Cu 69.5 kN, grease limiting speed 1,000 r/min, oil speed 1,400 r/min, mass about 15.2 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 180 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413036UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413036UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 74 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413036UTG mean?",
        "a": "Suffix reading on 413036UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413036UTG list two speeds, 1,000 and 1,400 r/min?",
        "a": "The lower figure, 1,000 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413036UTG at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413036UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413036utg",
      "4t-413036utg",
      "＊413036utg",
      "413036UTG",
      "4T-413036UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423036UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423036UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 180,
    "D_mm": 280,
    "B_mm": 93,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 745,
    "static_load_kN": 1050,
    "fatigue_load_limit_kN": 99.5,
    "limiting_speed_rpm": 1000,
    "max_rpm": 1000,
    "speed_oil_rpm": 1400,
    "weight_g": 19000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423036UTG belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Unlike a pair of single-row bearings, the TDO unit of 4T-423036UTG integrates both rows in one article: the 93 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Grease relubrication at the 1,000 r/min limiting speed must reach both roller rows; sustaining 1,400 r/min needs an oil supply with defined flow through the double cup. Because the unit is preset, mounting 4T-423036UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Mount 4T-423036UTG as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 180 mm bore the 4T-423036UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 745 kN C level.",
      "The 430 light plan keeps 4T-423036UTG narrower and faster than the 432 heavy execution of the same 180 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 50.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-423036UTG or the cones bottom out on the radius.",
      "Grease packs must leave free volume across the 93 mm width; over-greasing a unit churning near the 1,400 r/min oil-band speed raises temperature and expels the grease.",
      "Open 4T-423036UTG units have no seals: the housing must seal both rows or the 1,000 r/min grease figure is meaningless once contamination enters.",
      "The 745/1050 kN ratings and 99.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423036UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423036UTG?",
        "a": "4T-423036UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 180 mm bore, 280 mm outside diameter and 93 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 745 kN, C0 1050 kN, Cu 99.5 kN, grease limiting speed 1,000 r/min, oil speed 1,400 r/min, mass about 19 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 180 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423036UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423036UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 93 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423036UTG mean?",
        "a": "Suffix reading on 423036UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423036UTG list two speeds, 1,000 and 1,400 r/min?",
        "a": "The lower figure, 1,000 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423036UTG at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423036UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423036utg",
      "4t-423036utg",
      "＊423036utg",
      "423036UTG",
      "4T-423036UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323136UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323136UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 180,
    "D_mm": 300,
    "B_mm": 96,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1130,
    "static_load_kN": 1530,
    "fatigue_load_limit_kN": 144,
    "limiting_speed_rpm": 960,
    "max_rpm": 960,
    "speed_oil_rpm": 1400,
    "weight_g": 27200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-323136UTG at 180 mm bore, 300 mm OD and 96 mm overall width, with a grease limiting speed of 960 r/min and an oil ceiling of 1,400 r/min. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 180 mm bore the 432 execution carries a wider, heavier section than the 430. The 6.3 kN of dynamic capacity per millimetre of bore summarises the 1130 kN rating over the 180 mm bore — compare substitution candidates on this ratio and on the 96 mm width. Because the unit is preset, mounting 4T-323136UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-323136UTG.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 180 mm bore the 4T-323136UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1130 kN C level.",
      "The 432 heavy plan gives 4T-323136UTG its 96 mm width and 1130 kN rating at the 180 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 144 kN Cu.",
      "Grease packs must leave free volume across the 96 mm width; over-greasing a unit churning near the 1,400 r/min oil-band speed raises temperature and expels the grease.",
      "Open 4T-323136UTG units have no seals: the housing must seal both rows or the 960 r/min grease figure is meaningless once contamination enters.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 300 mm OD clamping uniformly around the circumference.",
      "The 1130/1530 kN ratings and 144 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323136UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323136UTG?",
        "a": "4T-323136UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 180 mm bore, 300 mm outside diameter and 96 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1130 kN, C0 1530 kN, Cu 144 kN, grease limiting speed 960 r/min, oil speed 1,400 r/min, mass about 27.2 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 180 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323136UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323136UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 96 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323136UTG mean?",
        "a": "Suffix reading on 323136UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323136UTG list two speeds, 960 and 1,400 r/min?",
        "a": "The lower figure, 960 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323136UTG at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323136UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323136utg",
      "4t-323136utg",
      "＊323136utg",
      "323136UTG",
      "4T-323136UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413136UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413136UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 180,
    "D_mm": 300,
    "B_mm": 96,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 910,
    "static_load_kN": 1190,
    "fatigue_load_limit_kN": 111,
    "limiting_speed_rpm": 940,
    "max_rpm": 940,
    "speed_oil_rpm": 1400,
    "weight_g": 25000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-413136UTG at 180 mm bore, 300 mm OD and 96 mm overall width, with a grease limiting speed of 940 r/min and an oil ceiling of 1,400 r/min. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 413136UTG reads accordingly. Axial capacity is bidirectional because the rows are opposed: 4T-413136UTG locates the shaft in both directions with C0 1190 kN behind the static check of the more heavily loaded row. TDO construction means the two cone assemblies of 4T-413136UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 180 mm shaft. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 180 mm size before ordering 4T-413136UTG.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 180 mm bore the 4T-413136UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 910 kN C level.",
      "The 430 light plan keeps 4T-413136UTG narrower and faster than the 432 heavy execution of the same 180 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 60.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-413136UTG or the cones bottom out on the radius.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-413136UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 910 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 910/1190 kN ratings and 111 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413136UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413136UTG?",
        "a": "4T-413136UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 180 mm bore, 300 mm outside diameter and 96 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 910 kN, C0 1190 kN, Cu 111 kN, grease limiting speed 940 r/min, oil speed 1,400 r/min, mass about 25 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 180 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413136UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413136UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 96 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413136UTG mean?",
        "a": "Suffix reading on 413136UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413136UTG list two speeds, 940 and 1,400 r/min?",
        "a": "The lower figure, 940 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413136UTG at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413136UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413136utg",
      "4t-413136utg",
      "＊413136utg",
      "413136UTG",
      "4T-413136UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423136UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423136UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 180,
    "D_mm": 300,
    "B_mm": 120,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1130,
    "static_load_kN": 1530,
    "fatigue_load_limit_kN": 144,
    "limiting_speed_rpm": 940,
    "max_rpm": 940,
    "speed_oil_rpm": 1400,
    "weight_g": 30100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423136UTG belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Reading the designation: the last two digits 36 are the bore code, ×5 = 180 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. The 6.3 kN of dynamic capacity per millimetre of bore summarises the 1130 kN rating over the 180 mm bore — compare substitution candidates on this ratio and on the 120 mm width. TDO construction means the two cone assemblies of 4T-423136UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 180 mm shaft. The open unit carries no seals; the housing of 4T-423136UTG must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 180 mm bore the 4T-423136UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1130 kN C level.",
      "The 430 light plan keeps 4T-423136UTG narrower and faster than the 432 heavy execution of the same 180 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-423136UTG near 940 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-423136UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Order by the full 423136UTG code including suffixes — U, X, DX, E1 and UTG variants share the 180 mm bore but are different articles with different internal geometry.",
      "The 1130/1530 kN ratings and 144 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423136UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423136UTG?",
        "a": "4T-423136UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 180 mm bore, 300 mm outside diameter and 120 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1130 kN, C0 1530 kN, Cu 144 kN, grease limiting speed 940 r/min, oil speed 1,400 r/min, mass about 30.1 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 180 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423136UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423136UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 120 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423136UTG mean?",
        "a": "Suffix reading on 423136UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423136UTG list two speeds, 940 and 1,400 r/min?",
        "a": "The lower figure, 940 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423136UTG at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423136UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423136utg",
      "4t-423136utg",
      "＊423136utg",
      "423136UTG",
      "4T-423136UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430236UUTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430236UUTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 180,
    "D_mm": 320,
    "B_mm": 127,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1380,
    "static_load_kN": 1780,
    "fatigue_load_limit_kN": 165,
    "limiting_speed_rpm": 890,
    "max_rpm": 890,
    "speed_oil_rpm": 1300,
    "weight_g": 39100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-430236UUTG denotes the light-duty 430-family TDO double-row series — a 180 mm bore double-row tapered unit rated 1380 kN basic dynamic and 1780 kN static. Unlike a pair of single-row bearings, the TDO unit of 4T-430236UUTG integrates both rows in one article: the 127 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Double-row capacity is not twice a single-row bearing: the printed 1380 kN C already accounts for load sharing between the two rows of 4T-430236UUTG, so apply it directly in the L10 calculation. TDO construction means the two cone assemblies of 4T-430236UUTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 180 mm shaft. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-430236UUTG are ground as a unit.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 180 mm bore the 4T-430236UUTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1380 kN C level.",
      "The 430 light plan keeps 4T-430236UUTG narrower and faster than the 432 heavy execution of the same 180 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Grease packs must leave free volume across the 127 mm width; over-greasing a unit churning near the 1,300 r/min oil-band speed raises temperature and expels the grease.",
      "Order by the full 430236UUTG code including suffixes — U, X, DX, E1 and UTG variants share the 180 mm bore but are different articles with different internal geometry.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 127 mm width, load spread and clearance logic of 4T-430236UUTG are unit-specific.",
      "The 1380/1780 kN ratings and 165 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430236UUTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430236UUTG?",
        "a": "4T-430236UUTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 180 mm bore, 320 mm outside diameter and 127 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1380 kN, C0 1780 kN, Cu 165 kN, grease limiting speed 890 r/min, oil speed 1,300 r/min, mass about 39.1 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 180 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430236UUTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430236UUTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 127 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430236UUTG mean?",
        "a": "Suffix reading on 430236UUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430236UUTG list two speeds, 890 and 1,300 r/min?",
        "a": "The lower figure, 890 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430236UUTG at 1,300 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430236UUTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430236uutg",
      "4t-430236uutg",
      "＊430236uutg",
      "430236UUTG",
      "4T-430236UUTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432236UUTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432236UUTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 180,
    "D_mm": 320,
    "B_mm": 192,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2260,
    "static_load_kN": 3350,
    "fatigue_load_limit_kN": 315,
    "limiting_speed_rpm": 890,
    "max_rpm": 890,
    "speed_oil_rpm": 1300,
    "weight_g": 63800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 180 mm shaft needing a compact two-direction thrust location, NTN lists 4T-432236UUTG, a TDO double-row 4T unit of 2260 kN C and 3350 kN C0 in the heavy-duty 432-family TDO double-row series. Suffix reading on 432236UUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles. The 70.0 mm radial section over the 180 mm bore carries two roller rows across the 192 mm width; abutment shoulders must clear both cone bores and the double-cup OD. Because the unit is preset, mounting 4T-432236UUTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-432236UUTG are ground as a unit.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 180 mm bore the 4T-432236UUTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2260 kN C level.",
      "The 432 heavy plan gives 4T-432236UUTG its 192 mm width and 2260 kN rating at the 180 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 315 kN Cu.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 320 mm OD clamping uniformly around the circumference.",
      "The internal clearance of 4T-432236UUTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Grease packs must leave free volume across the 192 mm width; over-greasing a unit churning near the 1,300 r/min oil-band speed raises temperature and expels the grease.",
      "The 2260/3350 kN ratings and 315 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432236UUTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432236UUTG?",
        "a": "4T-432236UUTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 180 mm bore, 320 mm outside diameter and 192 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2260 kN, C0 3350 kN, Cu 315 kN, grease limiting speed 890 r/min, oil speed 1,300 r/min, mass about 63.8 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 180 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432236UUTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432236UUTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 192 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432236UUTG mean?",
        "a": "Suffix reading on 432236UUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432236UUTG list two speeds, 890 and 1,300 r/min?",
        "a": "The lower figure, 890 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432236UUTG at 1,300 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432236UUTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432236uutg",
      "4t-432236uutg",
      "＊432236uutg",
      "432236UUTG",
      "4T-432236UUTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323038UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323038UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 190,
    "D_mm": 290,
    "B_mm": 75,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 790,
    "static_load_kN": 1110,
    "fatigue_load_limit_kN": 104,
    "limiting_speed_rpm": 950,
    "max_rpm": 950,
    "speed_oil_rpm": 1400,
    "weight_g": 17900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323038UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 190×290×75 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-323038UTG integrates both rows in one article: the 75 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The 50.0 mm radial section over the 190 mm bore carries two roller rows across the 75 mm width; abutment shoulders must clear both cone bores and the double-cup OD. TDO construction means the two cone assemblies of 4T-323038UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 190 mm shaft. Induction heating to max 120 °C is the standard fitting method at this 190 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 190 mm bore the 4T-323038UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 790 kN C level.",
      "The 432 heavy plan gives 4T-323038UTG its 75 mm width and 790 kN rating at the 190 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 104 kN Cu.",
      "The internal clearance of 4T-323038UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-323038UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 50.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-323038UTG or the cones bottom out on the radius.",
      "The 790/1110 kN ratings and 104 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323038UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323038UTG?",
        "a": "4T-323038UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 190 mm bore, 290 mm outside diameter and 75 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 790 kN, C0 1110 kN, Cu 104 kN, grease limiting speed 950 r/min, oil speed 1,400 r/min, mass about 17.9 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 190 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323038UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323038UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 75 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323038UTG mean?",
        "a": "Suffix reading on 323038UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323038UTG list two speeds, 950 and 1,400 r/min?",
        "a": "The lower figure, 950 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323038UTG at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323038UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323038utg",
      "4t-323038utg",
      "＊323038utg",
      "323038UTG",
      "4T-323038UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413038UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413038UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 190,
    "D_mm": 290,
    "B_mm": 75,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 555,
    "static_load_kN": 740,
    "fatigue_load_limit_kN": 69.5,
    "limiting_speed_rpm": 940,
    "max_rpm": 940,
    "speed_oil_rpm": 1400,
    "weight_g": 15900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413038UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 190×290×75 mm. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 413038UTG reads accordingly. The 50.0 mm radial section over the 190 mm bore carries two roller rows across the 75 mm width; abutment shoulders must clear both cone bores and the double-cup OD. Because the unit is preset, mounting 4T-413038UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Mount 4T-413038UTG as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 190 mm bore the 4T-413038UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 555 kN C level.",
      "The 430 light plan keeps 4T-413038UTG narrower and faster than the 432 heavy execution of the same 190 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-413038UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 290 mm OD clamping uniformly around the circumference.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 75 mm width, load spread and clearance logic of 4T-413038UTG are unit-specific.",
      "The 555/740 kN ratings and 69.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413038UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413038UTG?",
        "a": "4T-413038UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 190 mm bore, 290 mm outside diameter and 75 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 555 kN, C0 740 kN, Cu 69.5 kN, grease limiting speed 940 r/min, oil speed 1,400 r/min, mass about 15.9 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 190 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413038UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413038UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 75 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413038UTG mean?",
        "a": "Suffix reading on 413038UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413038UTG list two speeds, 940 and 1,400 r/min?",
        "a": "The lower figure, 940 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413038UTG at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413038UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413038utg",
      "4t-413038utg",
      "＊413038utg",
      "413038UTG",
      "4T-413038UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423038UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423038UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 190,
    "D_mm": 290,
    "B_mm": 94,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 790,
    "static_load_kN": 1110,
    "fatigue_load_limit_kN": 104,
    "limiting_speed_rpm": 940,
    "max_rpm": 940,
    "speed_oil_rpm": 1400,
    "weight_g": 16100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 190 mm shaft position as 4T-423038UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 94 mm. Suffix reading on 423038UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. The 50.0 mm radial section over the 190 mm bore carries two roller rows across the 94 mm width; abutment shoulders must clear both cone bores and the double-cup OD. The internal clearance of 4T-423038UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 94 mm overall width is the finished dimension. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-423038UTG are ground as a unit.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 190 mm bore the 4T-423038UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 790 kN C level.",
      "The 430 light plan keeps 4T-423038UTG narrower and faster than the 432 heavy execution of the same 190 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Grease packs must leave free volume across the 94 mm width; over-greasing a unit churning near the 1,400 r/min oil-band speed raises temperature and expels the grease.",
      "The 790 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Open 4T-423038UTG units have no seals: the housing must seal both rows or the 940 r/min grease figure is meaningless once contamination enters.",
      "The 790/1110 kN ratings and 104 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423038UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423038UTG?",
        "a": "4T-423038UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 190 mm bore, 290 mm outside diameter and 94 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 790 kN, C0 1110 kN, Cu 104 kN, grease limiting speed 940 r/min, oil speed 1,400 r/min, mass about 16.1 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 190 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423038UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423038UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 94 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423038UTG mean?",
        "a": "Suffix reading on 423038UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423038UTG list two speeds, 940 and 1,400 r/min?",
        "a": "The lower figure, 940 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423038UTG at 1,400 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423038UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423038utg",
      "4t-423038utg",
      "＊423038utg",
      "423038UTG",
      "4T-423038UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323138UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323138UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 190,
    "D_mm": 320,
    "B_mm": 104,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1260,
    "static_load_kN": 1710,
    "fatigue_load_limit_kN": 157,
    "limiting_speed_rpm": 900,
    "max_rpm": 900,
    "speed_oil_rpm": 1300,
    "weight_g": 33200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323138UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 190×320×104 mm. Reading the designation: the last two digits 38 are the bore code, ×5 = 190 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. The fatigue load limit Cu printed for 4T-323138UTG is 157 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. The internal clearance of 4T-323138UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 104 mm overall width is the finished dimension. With a rotating shaft a m6/n6 seat on the 190 mm journal and a located cup in the housing are typical practice for 4T-323138UTG.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 190 mm bore the 4T-323138UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1260 kN C level.",
      "The 432 heavy plan gives 4T-323138UTG its 104 mm width and 1260 kN rating at the 190 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 157 kN Cu.",
      "Order by the full 323138UTG code including suffixes — U, X, DX, E1 and UTG variants share the 190 mm bore but are different articles with different internal geometry.",
      "An unloaded 4T-323138UTG near 900 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 320 mm OD clamping uniformly around the circumference.",
      "The 1260/1710 kN ratings and 157 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323138UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323138UTG?",
        "a": "4T-323138UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 190 mm bore, 320 mm outside diameter and 104 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1260 kN, C0 1710 kN, Cu 157 kN, grease limiting speed 900 r/min, oil speed 1,300 r/min, mass about 33.2 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 190 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323138UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323138UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 104 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323138UTG mean?",
        "a": "Suffix reading on 323138UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323138UTG list two speeds, 900 and 1,300 r/min?",
        "a": "The lower figure, 900 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323138UTG at 1,300 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323138UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323138utg",
      "4t-323138utg",
      "＊323138utg",
      "323138UTG",
      "4T-323138UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413138UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413138UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 190,
    "D_mm": 320,
    "B_mm": 104,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1000,
    "static_load_kN": 1280,
    "fatigue_load_limit_kN": 118,
    "limiting_speed_rpm": 890,
    "max_rpm": 890,
    "speed_oil_rpm": 1300,
    "weight_g": 30300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413138UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 190×320×104 mm. Suffix reading on 413138UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Speed planning uses both catalogue columns: grease 890 r/min is the mechanical ceiling, oil 1,300 r/min with oil lubrication — a 410 r/min margin at this size. Because the unit is preset, mounting 4T-413138UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-413138UTG.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 190 mm bore the 4T-413138UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1000 kN C level.",
      "The 430 light plan keeps 4T-413138UTG narrower and faster than the 432 heavy execution of the same 190 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 1000 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Grease packs must leave free volume across the 104 mm width; over-greasing a unit churning near the 1,300 r/min oil-band speed raises temperature and expels the grease.",
      "The 1000 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 1000/1280 kN ratings and 118 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413138UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413138UTG?",
        "a": "4T-413138UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 190 mm bore, 320 mm outside diameter and 104 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1000 kN, C0 1280 kN, Cu 118 kN, grease limiting speed 890 r/min, oil speed 1,300 r/min, mass about 30.3 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 190 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413138UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413138UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 104 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413138UTG mean?",
        "a": "Suffix reading on 413138UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413138UTG list two speeds, 890 and 1,300 r/min?",
        "a": "The lower figure, 890 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413138UTG at 1,300 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413138UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413138utg",
      "4t-413138utg",
      "＊413138utg",
      "413138UTG",
      "4T-413138UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423138UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423138UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 190,
    "D_mm": 320,
    "B_mm": 130,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1260,
    "static_load_kN": 1710,
    "fatigue_load_limit_kN": 157,
    "limiting_speed_rpm": 890,
    "max_rpm": 890,
    "speed_oil_rpm": 1300,
    "weight_g": 37700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 190 mm shaft position as 4T-423138UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 130 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-423138UTG integrates both rows in one article: the 130 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The fatigue load limit Cu printed for 4T-423138UTG is 157 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. Because the unit is preset, mounting 4T-423138UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 190 mm size before ordering 4T-423138UTG.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 190 mm bore the 4T-423138UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1260 kN C level.",
      "The 430 light plan keeps 4T-423138UTG narrower and faster than the 432 heavy execution of the same 190 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The internal clearance of 4T-423138UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Grease packs must leave free volume across the 130 mm width; over-greasing a unit churning near the 1,300 r/min oil-band speed raises temperature and expels the grease.",
      "Order by the full 423138UTG code including suffixes — U, X, DX, E1 and UTG variants share the 190 mm bore but are different articles with different internal geometry.",
      "The 1260/1710 kN ratings and 157 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423138UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423138UTG?",
        "a": "4T-423138UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 190 mm bore, 320 mm outside diameter and 130 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1260 kN, C0 1710 kN, Cu 157 kN, grease limiting speed 890 r/min, oil speed 1,300 r/min, mass about 37.7 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 190 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423138UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423138UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 130 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423138UTG mean?",
        "a": "Suffix reading on 423138UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423138UTG list two speeds, 890 and 1,300 r/min?",
        "a": "The lower figure, 890 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423138UTG at 1,300 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423138UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423138utg",
      "4t-423138utg",
      "＊423138utg",
      "423138UTG",
      "4T-423138UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430238UUTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430238UUTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 190,
    "D_mm": 340,
    "B_mm": 133,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1570,
    "static_load_kN": 2010,
    "fatigue_load_limit_kN": 183,
    "limiting_speed_rpm": 840,
    "max_rpm": 840,
    "speed_oil_rpm": 1200,
    "weight_g": 47000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-430238UUTG denotes the light-duty 430-family TDO double-row series — a 190 mm bore double-row tapered unit rated 1570 kN basic dynamic and 2010 kN static. Suffix reading on 430238UUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles. Double-row capacity is not twice a single-row bearing: the printed 1570 kN C already accounts for load sharing between the two rows of 4T-430238UUTG, so apply it directly in the L10 calculation. TDO construction means the two cone assemblies of 4T-430238UUTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 190 mm shaft. Axial clamping of the double cup must be uniform around the 340 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 190 mm bore the 4T-430238UUTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1570 kN C level.",
      "The 430 light plan keeps 4T-430238UUTG narrower and faster than the 432 heavy execution of the same 190 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Open 4T-430238UUTG units have no seals: the housing must seal both rows or the 840 r/min grease figure is meaningless once contamination enters.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 340 mm OD clamping uniformly around the circumference.",
      "Order by the full 430238UUTG code including suffixes — U, X, DX, E1 and UTG variants share the 190 mm bore but are different articles with different internal geometry.",
      "The 1570/2010 kN ratings and 183 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430238UUTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430238UUTG?",
        "a": "4T-430238UUTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 190 mm bore, 340 mm outside diameter and 133 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1570 kN, C0 2010 kN, Cu 183 kN, grease limiting speed 840 r/min, oil speed 1,200 r/min, mass about 47 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 190 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430238UUTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430238UUTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 133 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430238UUTG mean?",
        "a": "Suffix reading on 430238UUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430238UUTG list two speeds, 840 and 1,200 r/min?",
        "a": "The lower figure, 840 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430238UUTG at 1,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430238UUTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430238uutg",
      "4t-430238uutg",
      "＊430238uutg",
      "430238UUTG",
      "4T-430238UUTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432238UUTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432238UUTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 190,
    "D_mm": 340,
    "B_mm": 204,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2530,
    "static_load_kN": 3700,
    "fatigue_load_limit_kN": 335,
    "limiting_speed_rpm": 840,
    "max_rpm": 840,
    "speed_oil_rpm": 1200,
    "weight_g": 75600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 190 mm shaft needing a compact two-direction thrust location, NTN lists 4T-432238UUTG, a TDO double-row 4T unit of 2530 kN C and 3700 kN C0 in the heavy-duty 432-family TDO double-row series. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 432238UUTG reads accordingly. The 75.0 mm radial section over the 190 mm bore carries two roller rows across the 204 mm width; abutment shoulders must clear both cone bores and the double-cup OD. Because the unit is preset, mounting 4T-432238UUTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Axial clamping of the double cup must be uniform around the 340 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 190 mm bore the 4T-432238UUTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2530 kN C level.",
      "The 432 heavy plan gives 4T-432238UUTG its 204 mm width and 2530 kN rating at the 190 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 335 kN Cu.",
      "Grease packs must leave free volume across the 204 mm width; over-greasing a unit churning near the 1,200 r/min oil-band speed raises temperature and expels the grease.",
      "The 2530 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "An unloaded 4T-432238UUTG near 840 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 2530/3700 kN ratings and 335 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432238UUTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432238UUTG?",
        "a": "4T-432238UUTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 190 mm bore, 340 mm outside diameter and 204 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2530 kN, C0 3700 kN, Cu 335 kN, grease limiting speed 840 r/min, oil speed 1,200 r/min, mass about 75.6 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 190 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432238UUTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432238UUTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 204 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432238UUTG mean?",
        "a": "Suffix reading on 432238UUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432238UUTG list two speeds, 840 and 1,200 r/min?",
        "a": "The lower figure, 840 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432238UUTG at 1,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432238UUTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432238uutg",
      "4t-432238uutg",
      "＊432238uutg",
      "432238UUTG",
      "4T-432238UUTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323040UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323040UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 200,
    "D_mm": 310,
    "B_mm": 82,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 920,
    "static_load_kN": 1320,
    "fatigue_load_limit_kN": 121,
    "limiting_speed_rpm": 900,
    "max_rpm": 900,
    "speed_oil_rpm": 1300,
    "weight_g": 22300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323040UTG is the NTN 4T catalogue entry for a 200×310×82 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 200 mm bore the 432 execution carries a wider, heavier section than the 430. The fatigue load limit Cu printed for 4T-323040UTG is 121 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. Because the unit is preset, mounting 4T-323040UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 200 mm size before ordering 4T-323040UTG.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 200 mm bore the 4T-323040UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 920 kN C level.",
      "The 432 heavy plan gives 4T-323040UTG its 82 mm width and 920 kN rating at the 200 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 121 kN Cu.",
      "The 55.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-323040UTG or the cones bottom out on the radius.",
      "An unloaded 4T-323040UTG near 900 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "An unloaded 4T-323040UTG near 900 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 920/1320 kN ratings and 121 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323040UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323040UTG?",
        "a": "4T-323040UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 200 mm bore, 310 mm outside diameter and 82 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 920 kN, C0 1320 kN, Cu 121 kN, grease limiting speed 900 r/min, oil speed 1,300 r/min, mass about 22.3 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 200 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323040UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323040UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 82 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323040UTG mean?",
        "a": "Suffix reading on 323040UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323040UTG list two speeds, 900 and 1,300 r/min?",
        "a": "The lower figure, 900 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323040UTG at 1,300 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323040UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323040utg",
      "4t-323040utg",
      "＊323040utg",
      "323040UTG",
      "4T-323040UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413040UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413040UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 200,
    "D_mm": 310,
    "B_mm": 82,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 680,
    "static_load_kN": 940,
    "fatigue_load_limit_kN": 87,
    "limiting_speed_rpm": 900,
    "max_rpm": 900,
    "speed_oil_rpm": 1300,
    "weight_g": 20900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413040UTG is the NTN 4T catalogue entry for a 200×310×82 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 413040UTG reads accordingly. The 55.0 mm radial section over the 200 mm bore carries two roller rows across the 82 mm width; abutment shoulders must clear both cone bores and the double-cup OD. The internal clearance of 4T-413040UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 82 mm overall width is the finished dimension. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-413040UTG's locating position.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 200 mm bore the 4T-413040UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 680 kN C level.",
      "The 430 light plan keeps 4T-413040UTG narrower and faster than the 432 heavy execution of the same 200 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 310 mm OD clamping uniformly around the circumference.",
      "The internal clearance of 4T-413040UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Open 4T-413040UTG units have no seals: the housing must seal both rows or the 900 r/min grease figure is meaningless once contamination enters.",
      "The 680/940 kN ratings and 87 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413040UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413040UTG?",
        "a": "4T-413040UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 200 mm bore, 310 mm outside diameter and 82 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 680 kN, C0 940 kN, Cu 87 kN, grease limiting speed 900 r/min, oil speed 1,300 r/min, mass about 20.9 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 200 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413040UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413040UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 82 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413040UTG mean?",
        "a": "Suffix reading on 413040UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413040UTG list two speeds, 900 and 1,300 r/min?",
        "a": "The lower figure, 900 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413040UTG at 1,300 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413040UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413040utg",
      "4t-413040utg",
      "＊413040utg",
      "413040UTG",
      "4T-413040UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423040UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423040UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 200,
    "D_mm": 310,
    "B_mm": 103,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 920,
    "static_load_kN": 1320,
    "fatigue_load_limit_kN": 121,
    "limiting_speed_rpm": 900,
    "max_rpm": 900,
    "speed_oil_rpm": 1300,
    "weight_g": 26600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 200 mm shaft needing a compact two-direction thrust location, NTN lists 4T-423040UTG, a TDO double-row 4T unit of 920 kN C and 1320 kN C0 in the light-duty 430-family TDO double-row series. Reading the designation: the last two digits 40 are the bore code, ×5 = 200 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. The fatigue load limit Cu printed for 4T-423040UTG is 121 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-423040UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 200 mm shaft. Induction heating to max 120 °C is the standard fitting method at this 200 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 200 mm bore the 4T-423040UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 920 kN C level.",
      "The 430 light plan keeps 4T-423040UTG narrower and faster than the 432 heavy execution of the same 200 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "At inspection do not mix the cone assemblies of 4T-423040UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Grease packs must leave free volume across the 103 mm width; over-greasing a unit churning near the 1,300 r/min oil-band speed raises temperature and expels the grease.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-423040UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 920/1320 kN ratings and 121 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423040UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423040UTG?",
        "a": "4T-423040UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 200 mm bore, 310 mm outside diameter and 103 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 920 kN, C0 1320 kN, Cu 121 kN, grease limiting speed 900 r/min, oil speed 1,300 r/min, mass about 26.6 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 200 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423040UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423040UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 103 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423040UTG mean?",
        "a": "Suffix reading on 423040UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423040UTG list two speeds, 900 and 1,300 r/min?",
        "a": "The lower figure, 900 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423040UTG at 1,300 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423040UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423040utg",
      "4t-423040utg",
      "＊423040utg",
      "423040UTG",
      "4T-423040UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323140UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323140UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 200,
    "D_mm": 340,
    "B_mm": 112,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1400,
    "static_load_kN": 1910,
    "fatigue_load_limit_kN": 173,
    "limiting_speed_rpm": 850,
    "max_rpm": 850,
    "speed_oil_rpm": 1200,
    "weight_g": 41800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323140UTG is the NTN 4T catalogue entry for a 200×340×112 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Reading the designation: the last two digits 40 are the bore code, ×5 = 200 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. The fatigue load limit Cu printed for 4T-323140UTG is 173 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-323140UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 200 mm shaft. At 1400 kN C the unit offers about 7.0 kN per millimetre of the 200 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 1,200 r/min.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 200 mm bore the 4T-323140UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1400 kN C level.",
      "The 432 heavy plan gives 4T-323140UTG its 112 mm width and 1400 kN rating at the 200 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 173 kN Cu.",
      "Open 4T-323140UTG units have no seals: the housing must seal both rows or the 850 r/min grease figure is meaningless once contamination enters.",
      "Open 4T-323140UTG units have no seals: the housing must seal both rows or the 850 r/min grease figure is meaningless once contamination enters.",
      "At inspection do not mix the cone assemblies of 4T-323140UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 1400/1910 kN ratings and 173 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323140UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323140UTG?",
        "a": "4T-323140UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 200 mm bore, 340 mm outside diameter and 112 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1400 kN, C0 1910 kN, Cu 173 kN, grease limiting speed 850 r/min, oil speed 1,200 r/min, mass about 41.8 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 200 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323140UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323140UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 112 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323140UTG mean?",
        "a": "Suffix reading on 323140UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323140UTG list two speeds, 850 and 1,200 r/min?",
        "a": "The lower figure, 850 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323140UTG at 1,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323140UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323140utg",
      "4t-323140utg",
      "＊323140utg",
      "323140UTG",
      "4T-323140UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413140UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413140UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 200,
    "D_mm": 340,
    "B_mm": 112,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1240,
    "static_load_kN": 1660,
    "fatigue_load_limit_kN": 150,
    "limiting_speed_rpm": 840,
    "max_rpm": 840,
    "speed_oil_rpm": 1200,
    "weight_g": 38600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413140UTG is the NTN 4T catalogue entry for a 200×340×112 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Suffix reading on 413140UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Speed planning uses both catalogue columns: grease 840 r/min is the mechanical ceiling, oil 1,200 r/min with oil lubrication — a 360 r/min margin at this size. The internal clearance of 4T-413140UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 112 mm overall width is the finished dimension. Axial clamping of the double cup must be uniform around the 340 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 200 mm bore the 4T-413140UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1240 kN C level.",
      "The 430 light plan keeps 4T-413140UTG narrower and faster than the 432 heavy execution of the same 200 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "At inspection do not mix the cone assemblies of 4T-413140UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-413140UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 340 mm OD clamping uniformly around the circumference.",
      "The 1240/1660 kN ratings and 150 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413140UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413140UTG?",
        "a": "4T-413140UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 200 mm bore, 340 mm outside diameter and 112 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1240 kN, C0 1660 kN, Cu 150 kN, grease limiting speed 840 r/min, oil speed 1,200 r/min, mass about 38.6 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 200 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413140UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413140UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 112 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413140UTG mean?",
        "a": "Suffix reading on 413140UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413140UTG list two speeds, 840 and 1,200 r/min?",
        "a": "The lower figure, 840 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413140UTG at 1,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413140UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413140utg",
      "4t-413140utg",
      "＊413140utg",
      "413140UTG",
      "4T-413140UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423140UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423140UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 200,
    "D_mm": 340,
    "B_mm": 140,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1400,
    "static_load_kN": 1910,
    "fatigue_load_limit_kN": 173,
    "limiting_speed_rpm": 840,
    "max_rpm": 840,
    "speed_oil_rpm": 1200,
    "weight_g": 47300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423140UTG is the NTN 4T catalogue entry for a 200×340×140 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Unlike a pair of single-row bearings, the TDO unit of 4T-423140UTG integrates both rows in one article: the 140 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The fatigue load limit Cu printed for 4T-423140UTG is 173 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-423140UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 200 mm shaft. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-423140UTG.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 200 mm bore the 4T-423140UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1400 kN C level.",
      "The 430 light plan keeps 4T-423140UTG narrower and faster than the 432 heavy execution of the same 200 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 140 mm width, load spread and clearance logic of 4T-423140UTG are unit-specific.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-423140UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "An unloaded 4T-423140UTG near 840 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 1400/1910 kN ratings and 173 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423140UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423140UTG?",
        "a": "4T-423140UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 200 mm bore, 340 mm outside diameter and 140 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1400 kN, C0 1910 kN, Cu 173 kN, grease limiting speed 840 r/min, oil speed 1,200 r/min, mass about 47.3 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 200 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423140UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423140UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 140 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423140UTG mean?",
        "a": "Suffix reading on 423140UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423140UTG list two speeds, 840 and 1,200 r/min?",
        "a": "The lower figure, 840 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423140UTG at 1,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423140UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423140utg",
      "4t-423140utg",
      "＊423140utg",
      "423140UTG",
      "4T-423140UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430240UUTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430240UUTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 200,
    "D_mm": 360,
    "B_mm": 142,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1730,
    "static_load_kN": 2210,
    "fatigue_load_limit_kN": 198,
    "limiting_speed_rpm": 800,
    "max_rpm": 800,
    "speed_oil_rpm": 1100,
    "weight_g": 55800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430240UUTG belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 430240UUTG reads accordingly. Speed planning uses both catalogue columns: grease 800 r/min is the mechanical ceiling, oil 1,100 r/min with oil lubrication — a 300 r/min margin at this size. Because the unit is preset, mounting 4T-430240UUTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. With a rotating shaft a m6/n6 seat on the 200 mm journal and a located cup in the housing are typical practice for 4T-430240UUTG.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 200 mm bore the 4T-430240UUTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1730 kN C level.",
      "The 430 light plan keeps 4T-430240UUTG narrower and faster than the 432 heavy execution of the same 200 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Open 4T-430240UUTG units have no seals: the housing must seal both rows or the 800 r/min grease figure is meaningless once contamination enters.",
      "Order by the full 430240UUTG code including suffixes — U, X, DX, E1 and UTG variants share the 200 mm bore but are different articles with different internal geometry.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-430240UUTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 1730/2210 kN ratings and 198 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430240UUTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430240UUTG?",
        "a": "4T-430240UUTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 200 mm bore, 360 mm outside diameter and 142 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1730 kN, C0 2210 kN, Cu 198 kN, grease limiting speed 800 r/min, oil speed 1,100 r/min, mass about 55.8 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 200 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430240UUTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430240UUTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 142 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430240UUTG mean?",
        "a": "Suffix reading on 430240UUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430240UUTG list two speeds, 800 and 1,100 r/min?",
        "a": "The lower figure, 800 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430240UUTG at 1,100 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430240UUTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430240uutg",
      "4t-430240uutg",
      "＊430240uutg",
      "430240UUTG",
      "4T-430240UUTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432240UUTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432240UUTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 200,
    "D_mm": 360,
    "B_mm": 218,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2900,
    "static_load_kN": 4250,
    "fatigue_load_limit_kN": 380,
    "limiting_speed_rpm": 800,
    "max_rpm": 800,
    "speed_oil_rpm": 1100,
    "weight_g": 91500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-432240UUTG is the NTN 4T catalogue entry for a 200×360×218 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 200 mm bore the 432 execution carries a wider, heavier section than the 430. Axial capacity is bidirectional because the rows are opposed: 4T-432240UUTG locates the shaft in both directions with C0 4250 kN behind the static check of the more heavily loaded row. The internal clearance of 4T-432240UUTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 218 mm overall width is the finished dimension. With a rotating shaft a m6/n6 seat on the 200 mm journal and a located cup in the housing are typical practice for 4T-432240UUTG.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 200 mm bore the 4T-432240UUTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2900 kN C level.",
      "The 432 heavy plan gives 4T-432240UUTG its 218 mm width and 2900 kN rating at the 200 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 380 kN Cu.",
      "Grease packs must leave free volume across the 218 mm width; over-greasing a unit churning near the 1,100 r/min oil-band speed raises temperature and expels the grease.",
      "The internal clearance of 4T-432240UUTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Order by the full 432240UUTG code including suffixes — U, X, DX, E1 and UTG variants share the 200 mm bore but are different articles with different internal geometry.",
      "The 2900/4250 kN ratings and 380 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432240UUTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432240UUTG?",
        "a": "4T-432240UUTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 200 mm bore, 360 mm outside diameter and 218 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2900 kN, C0 4250 kN, Cu 380 kN, grease limiting speed 800 r/min, oil speed 1,100 r/min, mass about 91.5 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 200 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432240UUTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432240UUTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 218 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432240UUTG mean?",
        "a": "Suffix reading on 432240UUTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; U marks the uprated/reinforced internal design, a separate order number with higher capacity than the basic execution; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432240UUTG list two speeds, 800 and 1,100 r/min?",
        "a": "The lower figure, 800 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432240UUTG at 1,100 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432240UUTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=197",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432240uutg",
      "4t-432240uutg",
      "＊432240uutg",
      "432240UUTG",
      "4T-432240UUTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323044UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323044UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 220,
    "D_mm": 340,
    "B_mm": 90,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1130,
    "static_load_kN": 1650,
    "fatigue_load_limit_kN": 148,
    "limiting_speed_rpm": 810,
    "max_rpm": 810,
    "speed_oil_rpm": 1200,
    "weight_g": 29800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 220 mm shaft position as 4T-323044UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 90 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-323044UTG integrates both rows in one article: the 90 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The fatigue load limit Cu printed for 4T-323044UTG is 148 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. The internal clearance of 4T-323044UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 90 mm overall width is the finished dimension. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 220 mm size before ordering 4T-323044UTG.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 220 mm bore the 4T-323044UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1130 kN C level.",
      "The 432 heavy plan gives 4T-323044UTG its 90 mm width and 1130 kN rating at the 220 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 148 kN Cu.",
      "Order by the full 323044UTG code including suffixes — U, X, DX, E1 and UTG variants share the 220 mm bore but are different articles with different internal geometry.",
      "The internal clearance of 4T-323044UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-323044UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 1130/1650 kN ratings and 148 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323044UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323044UTG?",
        "a": "4T-323044UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 220 mm bore, 340 mm outside diameter and 90 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1130 kN, C0 1650 kN, Cu 148 kN, grease limiting speed 810 r/min, oil speed 1,200 r/min, mass about 29.8 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 220 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323044UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323044UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 90 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323044UTG mean?",
        "a": "Suffix reading on 323044UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323044UTG list two speeds, 810 and 1,200 r/min?",
        "a": "The lower figure, 810 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323044UTG at 1,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323044UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323044utg",
      "4t-323044utg",
      "＊323044utg",
      "323044UTG",
      "4T-323044UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413044UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413044UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 220,
    "D_mm": 340,
    "B_mm": 90,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 765,
    "static_load_kN": 1060,
    "fatigue_load_limit_kN": 94.5,
    "limiting_speed_rpm": 810,
    "max_rpm": 810,
    "speed_oil_rpm": 1200,
    "weight_g": 27100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 220 mm shaft position as 4T-413044UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 90 mm. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 413044UTG reads accordingly. Speed planning uses both catalogue columns: grease 810 r/min is the mechanical ceiling, oil 1,200 r/min with oil lubrication — a 390 r/min margin at this size. Because the unit is preset, mounting 4T-413044UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. The open unit carries no seals; the housing of 4T-413044UTG must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 220 mm bore the 4T-413044UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 765 kN C level.",
      "The 430 light plan keeps 4T-413044UTG narrower and faster than the 432 heavy execution of the same 220 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 765 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Order by the full 413044UTG code including suffixes — U, X, DX, E1 and UTG variants share the 220 mm bore but are different articles with different internal geometry.",
      "Open 4T-413044UTG units have no seals: the housing must seal both rows or the 810 r/min grease figure is meaningless once contamination enters.",
      "The 765/1060 kN ratings and 94.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413044UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413044UTG?",
        "a": "4T-413044UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 220 mm bore, 340 mm outside diameter and 90 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 765 kN, C0 1060 kN, Cu 94.5 kN, grease limiting speed 810 r/min, oil speed 1,200 r/min, mass about 27.1 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 220 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413044UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413044UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 90 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413044UTG mean?",
        "a": "Suffix reading on 413044UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413044UTG list two speeds, 810 and 1,200 r/min?",
        "a": "The lower figure, 810 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413044UTG at 1,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413044UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413044utg",
      "4t-413044utg",
      "＊413044utg",
      "413044UTG",
      "4T-413044UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423044UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423044UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 220,
    "D_mm": 340,
    "B_mm": 113,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1130,
    "static_load_kN": 1650,
    "fatigue_load_limit_kN": 148,
    "limiting_speed_rpm": 810,
    "max_rpm": 810,
    "speed_oil_rpm": 1200,
    "weight_g": 33000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-423044UTG at 220 mm bore, 340 mm OD and 113 mm overall width, with a grease limiting speed of 810 r/min and an oil ceiling of 1,200 r/min. Suffix reading on 423044UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. The fatigue load limit Cu printed for 4T-423044UTG is 148 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. Because the unit is preset, mounting 4T-423044UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Induction heating to max 120 °C is the standard fitting method at this 220 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 220 mm bore the 4T-423044UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1130 kN C level.",
      "The 430 light plan keeps 4T-423044UTG narrower and faster than the 432 heavy execution of the same 220 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The internal clearance of 4T-423044UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Order by the full 423044UTG code including suffixes — U, X, DX, E1 and UTG variants share the 220 mm bore but are different articles with different internal geometry.",
      "Grease packs must leave free volume across the 113 mm width; over-greasing a unit churning near the 1,200 r/min oil-band speed raises temperature and expels the grease.",
      "The 1130/1650 kN ratings and 148 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423044UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423044UTG?",
        "a": "4T-423044UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 220 mm bore, 340 mm outside diameter and 113 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1130 kN, C0 1650 kN, Cu 148 kN, grease limiting speed 810 r/min, oil speed 1,200 r/min, mass about 33 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 220 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423044UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423044UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 113 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423044UTG mean?",
        "a": "Suffix reading on 423044UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423044UTG list two speeds, 810 and 1,200 r/min?",
        "a": "The lower figure, 810 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423044UTG at 1,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423044UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423044utg",
      "4t-423044utg",
      "＊423044utg",
      "423044UTG",
      "4T-423044UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323144UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323144UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 220,
    "D_mm": 370,
    "B_mm": 120,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1570,
    "static_load_kN": 2260,
    "fatigue_load_limit_kN": 199,
    "limiting_speed_rpm": 770,
    "max_rpm": 770,
    "speed_oil_rpm": 1100,
    "weight_g": 52200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 220 mm shaft position as 4T-323144UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 120 mm. Reading the designation: the last two digits 44 are the bore code, ×5 = 220 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. Selection: C 1570 kN against C0 2260 kN gives a C0/C ratio of 1.44; the two rows of 4T-323144UTG share the combined load as one bearing position. The internal clearance of 4T-323144UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 120 mm overall width is the finished dimension. Mount 4T-323144UTG as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 220 mm bore the 4T-323144UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1570 kN C level.",
      "The 432 heavy plan gives 4T-323144UTG its 120 mm width and 1570 kN rating at the 220 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 199 kN Cu.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 120 mm width, load spread and clearance logic of 4T-323144UTG are unit-specific.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-323144UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "At inspection do not mix the cone assemblies of 4T-323144UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 1570/2260 kN ratings and 199 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323144UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323144UTG?",
        "a": "4T-323144UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 220 mm bore, 370 mm outside diameter and 120 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1570 kN, C0 2260 kN, Cu 199 kN, grease limiting speed 770 r/min, oil speed 1,100 r/min, mass about 52.2 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 220 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323144UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323144UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 120 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323144UTG mean?",
        "a": "Suffix reading on 323144UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323144UTG list two speeds, 770 and 1,100 r/min?",
        "a": "The lower figure, 770 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323144UTG at 1,100 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323144UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323144utg",
      "4t-323144utg",
      "＊323144utg",
      "323144UTG",
      "4T-323144UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413144UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413144UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 220,
    "D_mm": 370,
    "B_mm": 120,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1420,
    "static_load_kN": 1920,
    "fatigue_load_limit_kN": 169,
    "limiting_speed_rpm": 760,
    "max_rpm": 760,
    "speed_oil_rpm": 1100,
    "weight_g": 47800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413144UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 220×370×120 mm. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 220 mm bore the 432 execution carries a wider, heavier section than the 430. Speed planning uses both catalogue columns: grease 760 r/min is the mechanical ceiling, oil 1,100 r/min with oil lubrication — a 340 r/min margin at this size. Because the unit is preset, mounting 4T-413144UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. With a rotating shaft a m6/n6 seat on the 220 mm journal and a located cup in the housing are typical practice for 4T-413144UTG.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 220 mm bore the 4T-413144UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1420 kN C level.",
      "The 430 light plan keeps 4T-413144UTG narrower and faster than the 432 heavy execution of the same 220 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The internal clearance of 4T-413144UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 370 mm OD clamping uniformly around the circumference.",
      "The 75.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-413144UTG or the cones bottom out on the radius.",
      "The 1420/1920 kN ratings and 169 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413144UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413144UTG?",
        "a": "4T-413144UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 220 mm bore, 370 mm outside diameter and 120 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1420 kN, C0 1920 kN, Cu 169 kN, grease limiting speed 760 r/min, oil speed 1,100 r/min, mass about 47.8 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 220 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413144UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413144UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 120 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413144UTG mean?",
        "a": "Suffix reading on 413144UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413144UTG list two speeds, 760 and 1,100 r/min?",
        "a": "The lower figure, 760 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413144UTG at 1,100 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413144UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413144utg",
      "4t-413144utg",
      "＊413144utg",
      "413144UTG",
      "4T-413144UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423144UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423144UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 220,
    "D_mm": 370,
    "B_mm": 150,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1570,
    "static_load_kN": 2260,
    "fatigue_load_limit_kN": 199,
    "limiting_speed_rpm": 760,
    "max_rpm": 760,
    "speed_oil_rpm": 1100,
    "weight_g": 58100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 220 mm shaft position as 4T-423144UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 150 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-423144UTG integrates both rows in one article: the 150 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Selection: C 1570 kN against C0 2260 kN gives a C0/C ratio of 1.44; the two rows of 4T-423144UTG share the combined load as one bearing position. The internal clearance of 4T-423144UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 150 mm overall width is the finished dimension. Axial clamping of the double cup must be uniform around the 370 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 220 mm bore the 4T-423144UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1570 kN C level.",
      "The 430 light plan keeps 4T-423144UTG narrower and faster than the 432 heavy execution of the same 220 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Order by the full 423144UTG code including suffixes — U, X, DX, E1 and UTG variants share the 220 mm bore but are different articles with different internal geometry.",
      "The 1570 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "An unloaded 4T-423144UTG near 760 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 1570/2260 kN ratings and 199 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423144UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423144UTG?",
        "a": "4T-423144UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 220 mm bore, 370 mm outside diameter and 150 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1570 kN, C0 2260 kN, Cu 199 kN, grease limiting speed 760 r/min, oil speed 1,100 r/min, mass about 58.1 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 220 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423144UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423144UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 150 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423144UTG mean?",
        "a": "Suffix reading on 423144UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423144UTG list two speeds, 760 and 1,100 r/min?",
        "a": "The lower figure, 760 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423144UTG at 1,100 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423144UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423144utg",
      "4t-423144utg",
      "＊423144utg",
      "423144UTG",
      "4T-423144UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430244UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430244UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 220,
    "D_mm": 400,
    "B_mm": 158,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1790,
    "static_load_kN": 2440,
    "fatigue_load_limit_kN": 212,
    "limiting_speed_rpm": 710,
    "max_rpm": 710,
    "speed_oil_rpm": 1000,
    "weight_g": 77000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-430244UTG is the NTN 4T catalogue entry for a 220×400×158 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Suffix reading on 430244UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. The fatigue load limit Cu printed for 4T-430244UTG is 212 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. Because the unit is preset, mounting 4T-430244UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-430244UTG's locating position.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 220 mm bore the 4T-430244UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1790 kN C level.",
      "The 430 light plan keeps 4T-430244UTG narrower and faster than the 432 heavy execution of the same 220 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Order by the full 430244UTG code including suffixes — U, X, DX, E1 and UTG variants share the 220 mm bore but are different articles with different internal geometry.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 400 mm OD clamping uniformly around the circumference.",
      "Grease packs must leave free volume across the 158 mm width; over-greasing a unit churning near the 1,000 r/min oil-band speed raises temperature and expels the grease.",
      "The 1790/2440 kN ratings and 212 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430244UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430244UTG?",
        "a": "4T-430244UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 220 mm bore, 400 mm outside diameter and 158 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1790 kN, C0 2440 kN, Cu 212 kN, grease limiting speed 710 r/min, oil speed 1,000 r/min, mass about 77 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 220 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430244UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430244UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 158 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430244UTG mean?",
        "a": "Suffix reading on 430244UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430244UTG list two speeds, 710 and 1,000 r/min?",
        "a": "The lower figure, 710 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430244UTG at 1,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430244UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430244utg",
      "4t-430244utg",
      "＊430244utg",
      "430244UTG",
      "4T-430244UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323048UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323048UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 240,
    "D_mm": 360,
    "B_mm": 92,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1170,
    "static_load_kN": 1770,
    "fatigue_load_limit_kN": 155,
    "limiting_speed_rpm": 730,
    "max_rpm": 730,
    "speed_oil_rpm": 1000,
    "weight_g": 32500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-323048UTG denotes the heavy-duty 432-family TDO double-row series — a 240 mm bore double-row tapered unit rated 1170 kN basic dynamic and 1770 kN static. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 323048UTG reads accordingly. Speed planning uses both catalogue columns: grease 730 r/min is the mechanical ceiling, oil 1,000 r/min with oil lubrication — a 270 r/min margin at this size. Because the unit is preset, mounting 4T-323048UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. With a rotating shaft a m6/n6 seat on the 240 mm journal and a located cup in the housing are typical practice for 4T-323048UTG.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 240 mm bore the 4T-323048UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1170 kN C level.",
      "The 432 heavy plan gives 4T-323048UTG its 92 mm width and 1170 kN rating at the 240 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 155 kN Cu.",
      "The 1170 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Order by the full 323048UTG code including suffixes — U, X, DX, E1 and UTG variants share the 240 mm bore but are different articles with different internal geometry.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-323048UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 1170/1770 kN ratings and 155 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323048UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323048UTG?",
        "a": "4T-323048UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 240 mm bore, 360 mm outside diameter and 92 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1170 kN, C0 1770 kN, Cu 155 kN, grease limiting speed 730 r/min, oil speed 1,000 r/min, mass about 32.5 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 240 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323048UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323048UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 92 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323048UTG mean?",
        "a": "Suffix reading on 323048UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323048UTG list two speeds, 730 and 1,000 r/min?",
        "a": "The lower figure, 730 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323048UTG at 1,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323048UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323048utg",
      "4t-323048utg",
      "＊323048utg",
      "323048UTG",
      "4T-323048UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413048UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413048UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 240,
    "D_mm": 360,
    "B_mm": 92,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 840,
    "static_load_kN": 1160,
    "fatigue_load_limit_kN": 101,
    "limiting_speed_rpm": 730,
    "max_rpm": 730,
    "speed_oil_rpm": 1000,
    "weight_g": 29100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-413048UTG denotes the light-duty 430-family TDO double-row series — a 240 mm bore double-row tapered unit rated 840 kN basic dynamic and 1160 kN static. Reading the designation: the last two digits 48 are the bore code, ×5 = 240 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. Speed planning uses both catalogue columns: grease 730 r/min is the mechanical ceiling, oil 1,000 r/min with oil lubrication — a 270 r/min margin at this size. The internal clearance of 4T-413048UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 92 mm overall width is the finished dimension. The open unit carries no seals; the housing of 4T-413048UTG must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 240 mm bore the 4T-413048UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 840 kN C level.",
      "The 430 light plan keeps 4T-413048UTG narrower and faster than the 432 heavy execution of the same 240 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-413048UTG near 730 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Open 4T-413048UTG units have no seals: the housing must seal both rows or the 730 r/min grease figure is meaningless once contamination enters.",
      "An unloaded 4T-413048UTG near 730 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 840/1160 kN ratings and 101 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413048UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413048UTG?",
        "a": "4T-413048UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 240 mm bore, 360 mm outside diameter and 92 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 840 kN, C0 1160 kN, Cu 101 kN, grease limiting speed 730 r/min, oil speed 1,000 r/min, mass about 29.1 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 240 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413048UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413048UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 92 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413048UTG mean?",
        "a": "Suffix reading on 413048UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413048UTG list two speeds, 730 and 1,000 r/min?",
        "a": "The lower figure, 730 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413048UTG at 1,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413048UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413048utg",
      "4t-413048utg",
      "＊413048utg",
      "413048UTG",
      "4T-413048UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423048UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423048UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 240,
    "D_mm": 360,
    "B_mm": 115,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1170,
    "static_load_kN": 1770,
    "fatigue_load_limit_kN": 155,
    "limiting_speed_rpm": 730,
    "max_rpm": 730,
    "speed_oil_rpm": 1000,
    "weight_g": 36300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423048UTG is the NTN 4T catalogue entry for a 240×360×115 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 240 mm bore the 432 execution carries a wider, heavier section than the 430. Speed planning uses both catalogue columns: grease 730 r/min is the mechanical ceiling, oil 1,000 r/min with oil lubrication — a 270 r/min margin at this size. TDO construction means the two cone assemblies of 4T-423048UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 240 mm shaft. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 240 mm size before ordering 4T-423048UTG.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 240 mm bore the 4T-423048UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1170 kN C level.",
      "The 430 light plan keeps 4T-423048UTG narrower and faster than the 432 heavy execution of the same 240 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-423048UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 115 mm width, load spread and clearance logic of 4T-423048UTG are unit-specific.",
      "Grease packs must leave free volume across the 115 mm width; over-greasing a unit churning near the 1,000 r/min oil-band speed raises temperature and expels the grease.",
      "The 1170/1770 kN ratings and 155 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423048UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423048UTG?",
        "a": "4T-423048UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 240 mm bore, 360 mm outside diameter and 115 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1170 kN, C0 1770 kN, Cu 155 kN, grease limiting speed 730 r/min, oil speed 1,000 r/min, mass about 36.3 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 240 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423048UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423048UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 115 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423048UTG mean?",
        "a": "Suffix reading on 423048UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423048UTG list two speeds, 730 and 1,000 r/min?",
        "a": "The lower figure, 730 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423048UTG at 1,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423048UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423048utg",
      "4t-423048utg",
      "＊423048utg",
      "423048UTG",
      "4T-423048UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323148UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323148UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 240,
    "D_mm": 400,
    "B_mm": 128,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1790,
    "static_load_kN": 2600,
    "fatigue_load_limit_kN": 223,
    "limiting_speed_rpm": 700,
    "max_rpm": 700,
    "speed_oil_rpm": 1000,
    "weight_g": 63400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-323148UTG denotes the heavy-duty 432-family TDO double-row series — a 240 mm bore double-row tapered unit rated 1790 kN basic dynamic and 2600 kN static. Suffix reading on 323148UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Selection: C 1790 kN against C0 2600 kN gives a C0/C ratio of 1.45; the two rows of 4T-323148UTG share the combined load as one bearing position. TDO construction means the two cone assemblies of 4T-323148UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 240 mm shaft. Mount 4T-323148UTG as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 240 mm bore the 4T-323148UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1790 kN C level.",
      "The 432 heavy plan gives 4T-323148UTG its 128 mm width and 1790 kN rating at the 240 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 223 kN Cu.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 400 mm OD clamping uniformly around the circumference.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 400 mm OD clamping uniformly around the circumference.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 128 mm width, load spread and clearance logic of 4T-323148UTG are unit-specific.",
      "The 1790/2600 kN ratings and 223 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323148UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323148UTG?",
        "a": "4T-323148UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 240 mm bore, 400 mm outside diameter and 128 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1790 kN, C0 2600 kN, Cu 223 kN, grease limiting speed 700 r/min, oil speed 1,000 r/min, mass about 63.4 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 240 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323148UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323148UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 128 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323148UTG mean?",
        "a": "Suffix reading on 323148UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323148UTG list two speeds, 700 and 1,000 r/min?",
        "a": "The lower figure, 700 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323148UTG at 1,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323148UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323148utg",
      "4t-323148utg",
      "＊323148utg",
      "323148UTG",
      "4T-323148UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413148UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413148UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 240,
    "D_mm": 400,
    "B_mm": 128,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1580,
    "static_load_kN": 2130,
    "fatigue_load_limit_kN": 183,
    "limiting_speed_rpm": 690,
    "max_rpm": 690,
    "speed_oil_rpm": 1000,
    "weight_g": 58500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413148UTG belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Unlike a pair of single-row bearings, the TDO unit of 4T-413148UTG integrates both rows in one article: the 128 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The 80.0 mm radial section over the 240 mm bore carries two roller rows across the 128 mm width; abutment shoulders must clear both cone bores and the double-cup OD. TDO construction means the two cone assemblies of 4T-413148UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 240 mm shaft. At 1580 kN C the unit offers about 6.6 kN per millimetre of the 240 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 1,000 r/min.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 240 mm bore the 4T-413148UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1580 kN C level.",
      "The 430 light plan keeps 4T-413148UTG narrower and faster than the 432 heavy execution of the same 240 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-413148UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "At inspection do not mix the cone assemblies of 4T-413148UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 80.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-413148UTG or the cones bottom out on the radius.",
      "The 1580/2130 kN ratings and 183 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413148UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413148UTG?",
        "a": "4T-413148UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 240 mm bore, 400 mm outside diameter and 128 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1580 kN, C0 2130 kN, Cu 183 kN, grease limiting speed 690 r/min, oil speed 1,000 r/min, mass about 58.5 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 240 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413148UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413148UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 128 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413148UTG mean?",
        "a": "Suffix reading on 413148UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413148UTG list two speeds, 690 and 1,000 r/min?",
        "a": "The lower figure, 690 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413148UTG at 1,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413148UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413148utg",
      "4t-413148utg",
      "＊413148utg",
      "413148UTG",
      "4T-413148UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423148UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423148UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 240,
    "D_mm": 400,
    "B_mm": 160,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1790,
    "static_load_kN": 2600,
    "fatigue_load_limit_kN": 223,
    "limiting_speed_rpm": 690,
    "max_rpm": 690,
    "speed_oil_rpm": 1000,
    "weight_g": 71400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-423148UTG denotes the light-duty 430-family TDO double-row series — a 240 mm bore double-row tapered unit rated 1790 kN basic dynamic and 2600 kN static. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 423148UTG reads accordingly. Selection: C 1790 kN against C0 2600 kN gives a C0/C ratio of 1.45; the two rows of 4T-423148UTG share the combined load as one bearing position. TDO construction means the two cone assemblies of 4T-423148UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 240 mm shaft. Axial clamping of the double cup must be uniform around the 400 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 240 mm bore the 4T-423148UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1790 kN C level.",
      "The 430 light plan keeps 4T-423148UTG narrower and faster than the 432 heavy execution of the same 240 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 1790 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "At inspection do not mix the cone assemblies of 4T-423148UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-423148UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 1790/2600 kN ratings and 223 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423148UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423148UTG?",
        "a": "4T-423148UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 240 mm bore, 400 mm outside diameter and 160 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1790 kN, C0 2600 kN, Cu 223 kN, grease limiting speed 690 r/min, oil speed 1,000 r/min, mass about 71.4 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 240 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423148UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423148UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 160 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423148UTG mean?",
        "a": "Suffix reading on 423148UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423148UTG list two speeds, 690 and 1,000 r/min?",
        "a": "The lower figure, 690 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423148UTG at 1,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423148UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423148utg",
      "4t-423148utg",
      "＊423148utg",
      "423148UTG",
      "4T-423148UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "430248UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-430248UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 240,
    "D_mm": 440,
    "B_mm": 165,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2150,
    "static_load_kN": 2960,
    "fatigue_load_limit_kN": 250,
    "limiting_speed_rpm": 640,
    "max_rpm": 640,
    "speed_oil_rpm": 900,
    "weight_g": 100000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 240 mm shaft position as 4T-430248UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 165 mm. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 240 mm bore the 432 execution carries a wider, heavier section than the 430. Speed planning uses both catalogue columns: grease 640 r/min is the mechanical ceiling, oil 900 r/min with oil lubrication — a 260 r/min margin at this size. TDO construction means the two cone assemblies of 4T-430248UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 240 mm shaft. The open unit carries no seals; the housing of 4T-430248UTG must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 240 mm bore the 4T-430248UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2150 kN C level.",
      "The 430 light plan keeps 4T-430248UTG narrower and faster than the 432 heavy execution of the same 240 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 2150 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "At inspection do not mix the cone assemblies of 4T-430248UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Grease packs must leave free volume across the 165 mm width; over-greasing a unit churning near the 900 r/min oil-band speed raises temperature and expels the grease.",
      "The 2150/2960 kN ratings and 250 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430248UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-430248UTG?",
        "a": "4T-430248UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 240 mm bore, 440 mm outside diameter and 165 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2150 kN, C0 2960 kN, Cu 250 kN, grease limiting speed 640 r/min, oil speed 900 r/min, mass about 100 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 240 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430248UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-430248UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 165 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 430248UTG mean?",
        "a": "Suffix reading on 430248UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-430248UTG list two speeds, 640 and 900 r/min?",
        "a": "The lower figure, 640 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430248UTG at 900 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "430248UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "430248utg",
      "4t-430248utg",
      "＊430248utg",
      "430248UTG",
      "4T-430248UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "432248UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-432248UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 240,
    "D_mm": 440,
    "B_mm": 266,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3750,
    "static_load_kN": 5500,
    "fatigue_load_limit_kN": 465,
    "limiting_speed_rpm": 640,
    "max_rpm": 640,
    "speed_oil_rpm": 900,
    "weight_g": 160000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 240 mm shaft position as 4T-432248UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 266 mm. Suffix reading on 432248UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. The 15.6 kN of dynamic capacity per millimetre of bore summarises the 3750 kN rating over the 240 mm bore — compare substitution candidates on this ratio and on the 266 mm width. The internal clearance of 4T-432248UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 266 mm overall width is the finished dimension. At 3750 kN C the unit offers about 15.6 kN per millimetre of the 240 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 900 r/min.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 240 mm bore the 4T-432248UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3750 kN C level.",
      "The 432 heavy plan gives 4T-432248UTG its 266 mm width and 3750 kN rating at the 240 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 465 kN Cu.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 440 mm OD clamping uniformly around the circumference.",
      "Grease packs must leave free volume across the 266 mm width; over-greasing a unit churning near the 900 r/min oil-band speed raises temperature and expels the grease.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 440 mm OD clamping uniformly around the circumference.",
      "The 3750/5500 kN ratings and 465 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-432248UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-432248UTG?",
        "a": "4T-432248UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 240 mm bore, 440 mm outside diameter and 266 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3750 kN, C0 5500 kN, Cu 465 kN, grease limiting speed 640 r/min, oil speed 900 r/min, mass about 160 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 240 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-432248UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-432248UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 266 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 432248UTG mean?",
        "a": "Suffix reading on 432248UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-432248UTG list two speeds, 640 and 900 r/min?",
        "a": "The lower figure, 640 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-432248UTG at 900 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "432248UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "432248utg",
      "4t-432248utg",
      "＊432248utg",
      "432248UTG",
      "4T-432248UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323052UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323052UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 260,
    "D_mm": 400,
    "B_mm": 104,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1470,
    "static_load_kN": 2190,
    "fatigue_load_limit_kN": 187,
    "limiting_speed_rpm": 670,
    "max_rpm": 670,
    "speed_oil_rpm": 1000,
    "weight_g": 47700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323052UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 260×400×104 mm. Suffix reading on 323052UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Catalogue mass of 4T-323052UTG is 47.7 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. The internal clearance of 4T-323052UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 104 mm overall width is the finished dimension. Axial clamping of the double cup must be uniform around the 400 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 260 mm bore the 4T-323052UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1470 kN C level.",
      "The 432 heavy plan gives 4T-323052UTG its 104 mm width and 1470 kN rating at the 260 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 187 kN Cu.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-323052UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 104 mm width, load spread and clearance logic of 4T-323052UTG are unit-specific.",
      "The internal clearance of 4T-323052UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 1470/2190 kN ratings and 187 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323052UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323052UTG?",
        "a": "4T-323052UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 260 mm bore, 400 mm outside diameter and 104 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1470 kN, C0 2190 kN, Cu 187 kN, grease limiting speed 670 r/min, oil speed 1,000 r/min, mass about 47.7 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 260 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323052UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323052UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 104 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323052UTG mean?",
        "a": "Suffix reading on 323052UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323052UTG list two speeds, 670 and 1,000 r/min?",
        "a": "The lower figure, 670 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323052UTG at 1,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323052UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323052utg",
      "4t-323052utg",
      "＊323052utg",
      "323052UTG",
      "4T-323052UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413052UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413052UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 260,
    "D_mm": 400,
    "B_mm": 104,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1070,
    "static_load_kN": 1540,
    "fatigue_load_limit_kN": 131,
    "limiting_speed_rpm": 670,
    "max_rpm": 670,
    "speed_oil_rpm": 1000,
    "weight_g": 43400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 260 mm shaft needing a compact two-direction thrust location, NTN lists 4T-413052UTG, a TDO double-row 4T unit of 1070 kN C and 1540 kN C0 in the light-duty 430-family TDO double-row series. Unlike a pair of single-row bearings, the TDO unit of 4T-413052UTG integrates both rows in one article: the 104 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Grease relubrication at the 670 r/min limiting speed must reach both roller rows; sustaining 1,000 r/min needs an oil supply with defined flow through the double cup. The internal clearance of 4T-413052UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 104 mm overall width is the finished dimension. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-413052UTG.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 260 mm bore the 4T-413052UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1070 kN C level.",
      "The 430 light plan keeps 4T-413052UTG narrower and faster than the 432 heavy execution of the same 260 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 104 mm width, load spread and clearance logic of 4T-413052UTG are unit-specific.",
      "Open 4T-413052UTG units have no seals: the housing must seal both rows or the 670 r/min grease figure is meaningless once contamination enters.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 400 mm OD clamping uniformly around the circumference.",
      "The 1070/1540 kN ratings and 131 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413052UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413052UTG?",
        "a": "4T-413052UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 260 mm bore, 400 mm outside diameter and 104 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1070 kN, C0 1540 kN, Cu 131 kN, grease limiting speed 670 r/min, oil speed 1,000 r/min, mass about 43.4 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 260 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413052UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413052UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 104 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413052UTG mean?",
        "a": "Suffix reading on 413052UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413052UTG list two speeds, 670 and 1,000 r/min?",
        "a": "The lower figure, 670 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413052UTG at 1,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413052UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413052utg",
      "4t-413052utg",
      "＊413052utg",
      "413052UTG",
      "4T-413052UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423052UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423052UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 260,
    "D_mm": 400,
    "B_mm": 130,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1470,
    "static_load_kN": 2190,
    "fatigue_load_limit_kN": 187,
    "limiting_speed_rpm": 670,
    "max_rpm": 670,
    "speed_oil_rpm": 1000,
    "weight_g": 53000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423052UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 260×400×130 mm. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 423052UTG reads accordingly. Catalogue mass of 4T-423052UTG is 53 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. The internal clearance of 4T-423052UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 130 mm overall width is the finished dimension. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 260 mm size before ordering 4T-423052UTG.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 260 mm bore the 4T-423052UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1470 kN C level.",
      "The 430 light plan keeps 4T-423052UTG narrower and faster than the 432 heavy execution of the same 260 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Open 4T-423052UTG units have no seals: the housing must seal both rows or the 670 r/min grease figure is meaningless once contamination enters.",
      "Open 4T-423052UTG units have no seals: the housing must seal both rows or the 670 r/min grease figure is meaningless once contamination enters.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 130 mm width, load spread and clearance logic of 4T-423052UTG are unit-specific.",
      "The 1470/2190 kN ratings and 187 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423052UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423052UTG?",
        "a": "4T-423052UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 260 mm bore, 400 mm outside diameter and 130 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1470 kN, C0 2190 kN, Cu 187 kN, grease limiting speed 670 r/min, oil speed 1,000 r/min, mass about 53 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 260 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423052UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423052UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 130 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423052UTG mean?",
        "a": "Suffix reading on 423052UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423052UTG list two speeds, 670 and 1,000 r/min?",
        "a": "The lower figure, 670 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423052UTG at 1,000 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423052UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423052utg",
      "4t-423052utg",
      "＊423052utg",
      "423052UTG",
      "4T-423052UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323152UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323152UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 260,
    "D_mm": 440,
    "B_mm": 144,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2510,
    "static_load_kN": 3750,
    "fatigue_load_limit_kN": 310,
    "limiting_speed_rpm": 640,
    "max_rpm": 640,
    "speed_oil_rpm": 910,
    "weight_g": 90500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 260 mm shaft needing a compact two-direction thrust location, NTN lists 4T-323152UTG, a TDO double-row 4T unit of 2510 kN C and 3750 kN C0 in the heavy-duty 432-family TDO double-row series. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 323152UTG reads accordingly. The 9.7 kN of dynamic capacity per millimetre of bore summarises the 2510 kN rating over the 260 mm bore — compare substitution candidates on this ratio and on the 144 mm width. TDO construction means the two cone assemblies of 4T-323152UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 260 mm shaft. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-323152UTG's locating position.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 260 mm bore the 4T-323152UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2510 kN C level.",
      "The 432 heavy plan gives 4T-323152UTG its 144 mm width and 2510 kN rating at the 260 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 310 kN Cu.",
      "Grease packs must leave free volume across the 144 mm width; over-greasing a unit churning near the 910 r/min oil-band speed raises temperature and expels the grease.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 440 mm OD clamping uniformly around the circumference.",
      "Grease packs must leave free volume across the 144 mm width; over-greasing a unit churning near the 910 r/min oil-band speed raises temperature and expels the grease.",
      "The 2510/3750 kN ratings and 310 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323152UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323152UTG?",
        "a": "4T-323152UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 260 mm bore, 440 mm outside diameter and 144 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2510 kN, C0 3750 kN, Cu 310 kN, grease limiting speed 640 r/min, oil speed 910 r/min, mass about 90.5 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 260 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323152UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323152UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 144 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323152UTG mean?",
        "a": "Suffix reading on 323152UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323152UTG list two speeds, 640 and 910 r/min?",
        "a": "The lower figure, 640 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323152UTG at 910 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323152UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323152utg",
      "4t-323152utg",
      "＊323152utg",
      "323152UTG",
      "4T-323152UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413152UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413152UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 260,
    "D_mm": 440,
    "B_mm": 144,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1920,
    "static_load_kN": 2630,
    "fatigue_load_limit_kN": 220,
    "limiting_speed_rpm": 630,
    "max_rpm": 630,
    "speed_oil_rpm": 910,
    "weight_g": 82000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 260 mm shaft needing a compact two-direction thrust location, NTN lists 4T-413152UTG, a TDO double-row 4T unit of 1920 kN C and 2630 kN C0 in the light-duty 430-family TDO double-row series. Reading the designation: the last two digits 52 are the bore code, ×5 = 260 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. The 7.4 kN of dynamic capacity per millimetre of bore summarises the 1920 kN rating over the 260 mm bore — compare substitution candidates on this ratio and on the 144 mm width. Because the unit is preset, mounting 4T-413152UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-413152UTG; the double cup must seat square across its full 144 mm width.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 260 mm bore the 4T-413152UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1920 kN C level.",
      "The 430 light plan keeps 4T-413152UTG narrower and faster than the 432 heavy execution of the same 260 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Open 4T-413152UTG units have no seals: the housing must seal both rows or the 630 r/min grease figure is meaningless once contamination enters.",
      "The 90.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-413152UTG or the cones bottom out on the radius.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-413152UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 1920/2630 kN ratings and 220 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413152UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413152UTG?",
        "a": "4T-413152UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 260 mm bore, 440 mm outside diameter and 144 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1920 kN, C0 2630 kN, Cu 220 kN, grease limiting speed 630 r/min, oil speed 910 r/min, mass about 82 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 260 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413152UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413152UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 144 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413152UTG mean?",
        "a": "Suffix reading on 413152UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413152UTG list two speeds, 630 and 910 r/min?",
        "a": "The lower figure, 630 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413152UTG at 910 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413152UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413152utg",
      "4t-413152utg",
      "＊413152utg",
      "413152UTG",
      "4T-413152UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423152UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423152UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 260,
    "D_mm": 440,
    "B_mm": 180,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2510,
    "static_load_kN": 3750,
    "fatigue_load_limit_kN": 310,
    "limiting_speed_rpm": 630,
    "max_rpm": 630,
    "speed_oil_rpm": 910,
    "weight_g": 100000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423152UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 260×440×180 mm. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 260 mm bore the 432 execution carries a wider, heavier section than the 430. The 9.7 kN of dynamic capacity per millimetre of bore summarises the 2510 kN rating over the 260 mm bore — compare substitution candidates on this ratio and on the 180 mm width. The internal clearance of 4T-423152UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 180 mm overall width is the finished dimension. Mount 4T-423152UTG as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 260 mm bore the 4T-423152UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2510 kN C level.",
      "The 430 light plan keeps 4T-423152UTG narrower and faster than the 432 heavy execution of the same 260 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-423152UTG near 630 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "At inspection do not mix the cone assemblies of 4T-423152UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 2510 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 2510/3750 kN ratings and 310 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423152UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423152UTG?",
        "a": "4T-423152UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 260 mm bore, 440 mm outside diameter and 180 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2510 kN, C0 3750 kN, Cu 310 kN, grease limiting speed 630 r/min, oil speed 910 r/min, mass about 100 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 260 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423152UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423152UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 180 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423152UTG mean?",
        "a": "Suffix reading on 423152UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423152UTG list two speeds, 630 and 910 r/min?",
        "a": "The lower figure, 630 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423152UTG at 910 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423152UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423152utg",
      "4t-423152utg",
      "＊423152utg",
      "423152UTG",
      "4T-423152UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323056UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323056UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 280,
    "D_mm": 420,
    "B_mm": 106,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1540,
    "static_load_kN": 2340,
    "fatigue_load_limit_kN": 196,
    "limiting_speed_rpm": 610,
    "max_rpm": 610,
    "speed_oil_rpm": 880,
    "weight_g": 50500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323056UTG belongs to the heavy-duty 432-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 280 mm bore the 432 execution carries a wider, heavier section than the 430. The 5.5 kN of dynamic capacity per millimetre of bore summarises the 1540 kN rating over the 280 mm bore — compare substitution candidates on this ratio and on the 106 mm width. Because the unit is preset, mounting 4T-323056UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-323056UTG; the double cup must seat square across its full 106 mm width.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 280 mm bore the 4T-323056UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1540 kN C level.",
      "The 432 heavy plan gives 4T-323056UTG its 106 mm width and 1540 kN rating at the 280 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 196 kN Cu.",
      "The 70.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-323056UTG or the cones bottom out on the radius.",
      "Open 4T-323056UTG units have no seals: the housing must seal both rows or the 610 r/min grease figure is meaningless once contamination enters.",
      "The internal clearance of 4T-323056UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 1540/2340 kN ratings and 196 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323056UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323056UTG?",
        "a": "4T-323056UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 280 mm bore, 420 mm outside diameter and 106 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1540 kN, C0 2340 kN, Cu 196 kN, grease limiting speed 610 r/min, oil speed 880 r/min, mass about 50.5 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 280 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323056UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323056UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 106 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323056UTG mean?",
        "a": "Suffix reading on 323056UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323056UTG list two speeds, 610 and 880 r/min?",
        "a": "The lower figure, 610 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323056UTG at 880 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323056UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=201",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323056utg",
      "4t-323056utg",
      "＊323056utg",
      "323056UTG",
      "4T-323056UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413056UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413056UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 280,
    "D_mm": 420,
    "B_mm": 106,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1140,
    "static_load_kN": 1630,
    "fatigue_load_limit_kN": 137,
    "limiting_speed_rpm": 620,
    "max_rpm": 620,
    "speed_oil_rpm": 880,
    "weight_g": 46000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-413056UTG at 280 mm bore, 420 mm OD and 106 mm overall width, with a grease limiting speed of 620 r/min and an oil ceiling of 880 r/min. Unlike a pair of single-row bearings, the TDO unit of 4T-413056UTG integrates both rows in one article: the 106 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The 4.1 kN of dynamic capacity per millimetre of bore summarises the 1140 kN rating over the 280 mm bore — compare substitution candidates on this ratio and on the 106 mm width. TDO construction means the two cone assemblies of 4T-413056UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 280 mm shaft. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-413056UTG.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 280 mm bore the 4T-413056UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1140 kN C level.",
      "The 430 light plan keeps 4T-413056UTG narrower and faster than the 432 heavy execution of the same 280 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Order by the full 413056UTG code including suffixes — U, X, DX, E1 and UTG variants share the 280 mm bore but are different articles with different internal geometry.",
      "The 1140 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Order by the full 413056UTG code including suffixes — U, X, DX, E1 and UTG variants share the 280 mm bore but are different articles with different internal geometry.",
      "The 1140/1630 kN ratings and 137 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413056UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413056UTG?",
        "a": "4T-413056UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 280 mm bore, 420 mm outside diameter and 106 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1140 kN, C0 1630 kN, Cu 137 kN, grease limiting speed 620 r/min, oil speed 880 r/min, mass about 46 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 280 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413056UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413056UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 106 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413056UTG mean?",
        "a": "Suffix reading on 413056UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413056UTG list two speeds, 620 and 880 r/min?",
        "a": "The lower figure, 620 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413056UTG at 880 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413056UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413056utg",
      "4t-413056utg",
      "＊413056utg",
      "413056UTG",
      "4T-413056UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423056UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423056UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 280,
    "D_mm": 420,
    "B_mm": 133,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1540,
    "static_load_kN": 2340,
    "fatigue_load_limit_kN": 196,
    "limiting_speed_rpm": 620,
    "max_rpm": 620,
    "speed_oil_rpm": 880,
    "weight_g": 56800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423056UTG belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Reading the designation: the last two digits 56 are the bore code, ×5 = 280 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. The 5.5 kN of dynamic capacity per millimetre of bore summarises the 1540 kN rating over the 280 mm bore — compare substitution candidates on this ratio and on the 133 mm width. Because the unit is preset, mounting 4T-423056UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. With a rotating shaft a m6/n6 seat on the 280 mm journal and a located cup in the housing are typical practice for 4T-423056UTG.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 280 mm bore the 4T-423056UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1540 kN C level.",
      "The 430 light plan keeps 4T-423056UTG narrower and faster than the 432 heavy execution of the same 280 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "At inspection do not mix the cone assemblies of 4T-423056UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-423056UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 133 mm width, load spread and clearance logic of 4T-423056UTG are unit-specific.",
      "The 1540/2340 kN ratings and 196 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423056UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423056UTG?",
        "a": "4T-423056UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 280 mm bore, 420 mm outside diameter and 133 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1540 kN, C0 2340 kN, Cu 196 kN, grease limiting speed 620 r/min, oil speed 880 r/min, mass about 56.8 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 280 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423056UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423056UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 133 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423056UTG mean?",
        "a": "Suffix reading on 423056UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423056UTG list two speeds, 620 and 880 r/min?",
        "a": "The lower figure, 620 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423056UTG at 880 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423056UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423056utg",
      "4t-423056utg",
      "＊423056utg",
      "423056UTG",
      "4T-423056UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323156UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323156UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 280,
    "D_mm": 460,
    "B_mm": 146,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2480,
    "static_load_kN": 3650,
    "fatigue_load_limit_kN": 300,
    "limiting_speed_rpm": 590,
    "max_rpm": 590,
    "speed_oil_rpm": 830,
    "weight_g": 93600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-323156UTG at 280 mm bore, 460 mm OD and 146 mm overall width, with a grease limiting speed of 590 r/min and an oil ceiling of 830 r/min. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 323156UTG reads accordingly. The 90.0 mm radial section over the 280 mm bore carries two roller rows across the 146 mm width; abutment shoulders must clear both cone bores and the double-cup OD. Because the unit is preset, mounting 4T-323156UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-323156UTG's locating position.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 280 mm bore the 4T-323156UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2480 kN C level.",
      "The 432 heavy plan gives 4T-323156UTG its 146 mm width and 2480 kN rating at the 280 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 300 kN Cu.",
      "An unloaded 4T-323156UTG near 590 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 90.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-323156UTG or the cones bottom out on the radius.",
      "The 2480 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 2480/3650 kN ratings and 300 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323156UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323156UTG?",
        "a": "4T-323156UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 280 mm bore, 460 mm outside diameter and 146 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2480 kN, C0 3650 kN, Cu 300 kN, grease limiting speed 590 r/min, oil speed 830 r/min, mass about 93.6 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 280 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323156UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323156UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 146 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323156UTG mean?",
        "a": "Suffix reading on 323156UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323156UTG list two speeds, 590 and 830 r/min?",
        "a": "The lower figure, 590 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323156UTG at 830 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323156UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323156utg",
      "4t-323156utg",
      "＊323156utg",
      "323156UTG",
      "4T-323156UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413156UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413156UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 280,
    "D_mm": 460,
    "B_mm": 146,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2100,
    "static_load_kN": 2900,
    "fatigue_load_limit_kN": 239,
    "limiting_speed_rpm": 580,
    "max_rpm": 580,
    "speed_oil_rpm": 830,
    "weight_g": 85500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-413156UTG at 280 mm bore, 460 mm OD and 146 mm overall width, with a grease limiting speed of 580 r/min and an oil ceiling of 830 r/min. Suffix reading on 413156UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Double-row capacity is not twice a single-row bearing: the printed 2100 kN C already accounts for load sharing between the two rows of 4T-413156UTG, so apply it directly in the L10 calculation. TDO construction means the two cone assemblies of 4T-413156UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 280 mm shaft. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-413156UTG are ground as a unit.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 280 mm bore the 4T-413156UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2100 kN C level.",
      "The 430 light plan keeps 4T-413156UTG narrower and faster than the 432 heavy execution of the same 280 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "At inspection do not mix the cone assemblies of 4T-413156UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "An unloaded 4T-413156UTG near 580 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-413156UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 2100/2900 kN ratings and 239 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413156UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413156UTG?",
        "a": "4T-413156UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 280 mm bore, 460 mm outside diameter and 146 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2100 kN, C0 2900 kN, Cu 239 kN, grease limiting speed 580 r/min, oil speed 830 r/min, mass about 85.5 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 280 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413156UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413156UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 146 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413156UTG mean?",
        "a": "Suffix reading on 413156UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413156UTG list two speeds, 580 and 830 r/min?",
        "a": "The lower figure, 580 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413156UTG at 830 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413156UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413156utg",
      "4t-413156utg",
      "＊413156utg",
      "413156UTG",
      "4T-413156UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423156UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423156UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 280,
    "D_mm": 460,
    "B_mm": 183,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2480,
    "static_load_kN": 3650,
    "fatigue_load_limit_kN": 300,
    "limiting_speed_rpm": 580,
    "max_rpm": 580,
    "speed_oil_rpm": 830,
    "weight_g": 110000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423156UTG belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 280 mm bore the 432 execution carries a wider, heavier section than the 430. The 90.0 mm radial section over the 280 mm bore carries two roller rows across the 183 mm width; abutment shoulders must clear both cone bores and the double-cup OD. TDO construction means the two cone assemblies of 4T-423156UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 280 mm shaft. Mount 4T-423156UTG as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 280 mm bore the 4T-423156UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2480 kN C level.",
      "The 430 light plan keeps 4T-423156UTG narrower and faster than the 432 heavy execution of the same 280 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 90.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-423156UTG or the cones bottom out on the radius.",
      "An unloaded 4T-423156UTG near 580 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The internal clearance of 4T-423156UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 2480/3650 kN ratings and 300 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423156UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423156UTG?",
        "a": "4T-423156UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 280 mm bore, 460 mm outside diameter and 183 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2480 kN, C0 3650 kN, Cu 300 kN, grease limiting speed 580 r/min, oil speed 830 r/min, mass about 110 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 280 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423156UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423156UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 183 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423156UTG mean?",
        "a": "Suffix reading on 423156UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423156UTG list two speeds, 580 and 830 r/min?",
        "a": "The lower figure, 580 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423156UTG at 830 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423156UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423156utg",
      "4t-423156utg",
      "＊423156utg",
      "423156UTG",
      "4T-423156UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323060UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323060UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 300,
    "D_mm": 460,
    "B_mm": 118,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2070,
    "static_load_kN": 3150,
    "fatigue_load_limit_kN": 257,
    "limiting_speed_rpm": 570,
    "max_rpm": 570,
    "speed_oil_rpm": 810,
    "weight_g": 69200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323060UTG is the NTN 4T catalogue entry for a 300×460×118 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 323060UTG reads accordingly. Axial capacity is bidirectional because the rows are opposed: 4T-323060UTG locates the shaft in both directions with C0 3150 kN behind the static check of the more heavily loaded row. Because the unit is preset, mounting 4T-323060UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-323060UTG are ground as a unit.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 300 mm bore the 4T-323060UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2070 kN C level.",
      "The 432 heavy plan gives 4T-323060UTG its 118 mm width and 2070 kN rating at the 300 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 257 kN Cu.",
      "At inspection do not mix the cone assemblies of 4T-323060UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Open 4T-323060UTG units have no seals: the housing must seal both rows or the 570 r/min grease figure is meaningless once contamination enters.",
      "The 80.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-323060UTG or the cones bottom out on the radius.",
      "The 2070/3150 kN ratings and 257 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323060UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323060UTG?",
        "a": "4T-323060UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 300 mm bore, 460 mm outside diameter and 118 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2070 kN, C0 3150 kN, Cu 257 kN, grease limiting speed 570 r/min, oil speed 810 r/min, mass about 69.2 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 300 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323060UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323060UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 118 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323060UTG mean?",
        "a": "Suffix reading on 323060UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323060UTG list two speeds, 570 and 810 r/min?",
        "a": "The lower figure, 570 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323060UTG at 810 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323060UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323060utg",
      "4t-323060utg",
      "＊323060utg",
      "323060UTG",
      "4T-323060UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413060UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413060UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 300,
    "D_mm": 460,
    "B_mm": 118,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1370,
    "static_load_kN": 1990,
    "fatigue_load_limit_kN": 163,
    "limiting_speed_rpm": 570,
    "max_rpm": 570,
    "speed_oil_rpm": 810,
    "weight_g": 65600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413060UTG is the NTN 4T catalogue entry for a 300×460×118 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Suffix reading on 413060UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. The fatigue load limit Cu printed for 4T-413060UTG is 163 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. The internal clearance of 4T-413060UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 118 mm overall width is the finished dimension. At 1370 kN C the unit offers about 4.6 kN per millimetre of the 300 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 810 r/min.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 300 mm bore the 4T-413060UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1370 kN C level.",
      "The 430 light plan keeps 4T-413060UTG narrower and faster than the 432 heavy execution of the same 300 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 1370 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 1370 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 118 mm width, load spread and clearance logic of 4T-413060UTG are unit-specific.",
      "The 1370/1990 kN ratings and 163 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413060UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413060UTG?",
        "a": "4T-413060UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 300 mm bore, 460 mm outside diameter and 118 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1370 kN, C0 1990 kN, Cu 163 kN, grease limiting speed 570 r/min, oil speed 810 r/min, mass about 65.6 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 300 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413060UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413060UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 118 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413060UTG mean?",
        "a": "Suffix reading on 413060UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413060UTG list two speeds, 570 and 810 r/min?",
        "a": "The lower figure, 570 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413060UTG at 810 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413060UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413060utg",
      "4t-413060utg",
      "＊413060utg",
      "413060UTG",
      "4T-413060UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423060UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423060UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 300,
    "D_mm": 460,
    "B_mm": 148,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2070,
    "static_load_kN": 3150,
    "fatigue_load_limit_kN": 257,
    "limiting_speed_rpm": 570,
    "max_rpm": 570,
    "speed_oil_rpm": 810,
    "weight_g": 77800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 300 mm shaft needing a compact two-direction thrust location, NTN lists 4T-423060UTG, a TDO double-row 4T unit of 2070 kN C and 3150 kN C0 in the light-duty 430-family TDO double-row series. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 300 mm bore the 432 execution carries a wider, heavier section than the 430. Axial capacity is bidirectional because the rows are opposed: 4T-423060UTG locates the shaft in both directions with C0 3150 kN behind the static check of the more heavily loaded row. TDO construction means the two cone assemblies of 4T-423060UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 300 mm shaft. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-423060UTG; the double cup must seat square across its full 148 mm width.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 300 mm bore the 4T-423060UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2070 kN C level.",
      "The 430 light plan keeps 4T-423060UTG narrower and faster than the 432 heavy execution of the same 300 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 460 mm OD clamping uniformly around the circumference.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-423060UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Open 4T-423060UTG units have no seals: the housing must seal both rows or the 570 r/min grease figure is meaningless once contamination enters.",
      "The 2070/3150 kN ratings and 257 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423060UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423060UTG?",
        "a": "4T-423060UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 300 mm bore, 460 mm outside diameter and 148 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2070 kN, C0 3150 kN, Cu 257 kN, grease limiting speed 570 r/min, oil speed 810 r/min, mass about 77.8 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 300 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423060UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423060UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 148 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423060UTG mean?",
        "a": "Suffix reading on 423060UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423060UTG list two speeds, 570 and 810 r/min?",
        "a": "The lower figure, 570 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423060UTG at 810 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423060UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423060utg",
      "4t-423060utg",
      "＊423060utg",
      "423060UTG",
      "4T-423060UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323160UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323160UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 300,
    "D_mm": 500,
    "B_mm": 160,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2690,
    "static_load_kN": 4050,
    "fatigue_load_limit_kN": 325,
    "limiting_speed_rpm": 540,
    "max_rpm": 540,
    "speed_oil_rpm": 770,
    "weight_g": 130000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323160UTG is the NTN 4T catalogue entry for a 300×500×160 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 300 mm bore the 432 execution carries a wider, heavier section than the 430. Axial capacity is bidirectional because the rows are opposed: 4T-323160UTG locates the shaft in both directions with C0 4050 kN behind the static check of the more heavily loaded row. TDO construction means the two cone assemblies of 4T-323160UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 300 mm shaft. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 300 mm size before ordering 4T-323160UTG.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 300 mm bore the 4T-323160UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2690 kN C level.",
      "The 432 heavy plan gives 4T-323160UTG its 160 mm width and 2690 kN rating at the 300 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 325 kN Cu.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 160 mm width, load spread and clearance logic of 4T-323160UTG are unit-specific.",
      "The 100.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-323160UTG or the cones bottom out on the radius.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 500 mm OD clamping uniformly around the circumference.",
      "The 2690/4050 kN ratings and 325 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323160UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323160UTG?",
        "a": "4T-323160UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 300 mm bore, 500 mm outside diameter and 160 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2690 kN, C0 4050 kN, Cu 325 kN, grease limiting speed 540 r/min, oil speed 770 r/min, mass about 130 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 300 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323160UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323160UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 160 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323160UTG mean?",
        "a": "Suffix reading on 323160UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323160UTG list two speeds, 540 and 770 r/min?",
        "a": "The lower figure, 540 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323160UTG at 770 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323160UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323160utg",
      "4t-323160utg",
      "＊323160utg",
      "323160UTG",
      "4T-323160UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413160UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413160UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 300,
    "D_mm": 500,
    "B_mm": 160,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2580,
    "static_load_kN": 3600,
    "fatigue_load_limit_kN": 290,
    "limiting_speed_rpm": 530,
    "max_rpm": 530,
    "speed_oil_rpm": 770,
    "weight_g": 110000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413160UTG is the NTN 4T catalogue entry for a 300×500×160 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Unlike a pair of single-row bearings, the TDO unit of 4T-413160UTG integrates both rows in one article: the 160 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Selection: C 2580 kN against C0 3600 kN gives a C0/C ratio of 1.40; the two rows of 4T-413160UTG share the combined load as one bearing position. The internal clearance of 4T-413160UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 160 mm overall width is the finished dimension. The open unit carries no seals; the housing of 4T-413160UTG must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 300 mm bore the 4T-413160UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2580 kN C level.",
      "The 430 light plan keeps 4T-413160UTG narrower and faster than the 432 heavy execution of the same 300 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 500 mm OD clamping uniformly around the circumference.",
      "An unloaded 4T-413160UTG near 530 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 2580 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 2580/3600 kN ratings and 290 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413160UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413160UTG?",
        "a": "4T-413160UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 300 mm bore, 500 mm outside diameter and 160 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2580 kN, C0 3600 kN, Cu 290 kN, grease limiting speed 530 r/min, oil speed 770 r/min, mass about 110 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 300 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413160UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413160UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 160 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413160UTG mean?",
        "a": "Suffix reading on 413160UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413160UTG list two speeds, 530 and 770 r/min?",
        "a": "The lower figure, 530 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413160UTG at 770 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413160UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413160utg",
      "4t-413160utg",
      "＊413160utg",
      "413160UTG",
      "4T-413160UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423160UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423160UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 300,
    "D_mm": 500,
    "B_mm": 200,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2690,
    "static_load_kN": 4050,
    "fatigue_load_limit_kN": 325,
    "limiting_speed_rpm": 530,
    "max_rpm": 530,
    "speed_oil_rpm": 770,
    "weight_g": 140000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 300 mm shaft needing a compact two-direction thrust location, NTN lists 4T-423160UTG, a TDO double-row 4T unit of 2690 kN C and 4050 kN C0 in the light-duty 430-family TDO double-row series. Reading the designation: the last two digits 60 are the bore code, ×5 = 300 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. Axial capacity is bidirectional because the rows are opposed: 4T-423160UTG locates the shaft in both directions with C0 4050 kN behind the static check of the more heavily loaded row. The internal clearance of 4T-423160UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 200 mm overall width is the finished dimension. Induction heating to max 120 °C is the standard fitting method at this 300 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 300 mm bore the 4T-423160UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2690 kN C level.",
      "The 430 light plan keeps 4T-423160UTG narrower and faster than the 432 heavy execution of the same 300 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Order by the full 423160UTG code including suffixes — U, X, DX, E1 and UTG variants share the 300 mm bore but are different articles with different internal geometry.",
      "An unloaded 4T-423160UTG near 530 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Order by the full 423160UTG code including suffixes — U, X, DX, E1 and UTG variants share the 300 mm bore but are different articles with different internal geometry.",
      "The 2690/4050 kN ratings and 325 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423160UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423160UTG?",
        "a": "4T-423160UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 300 mm bore, 500 mm outside diameter and 200 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2690 kN, C0 4050 kN, Cu 325 kN, grease limiting speed 530 r/min, oil speed 770 r/min, mass about 140 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 300 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423160UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423160UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 200 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423160UTG mean?",
        "a": "Suffix reading on 423160UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423160UTG list two speeds, 530 and 770 r/min?",
        "a": "The lower figure, 530 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423160UTG at 770 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423160UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423160utg",
      "4t-423160utg",
      "＊423160utg",
      "423160UTG",
      "4T-423160UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323064UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323064UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 320,
    "D_mm": 480,
    "B_mm": 121,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2030,
    "static_load_kN": 3100,
    "fatigue_load_limit_kN": 247,
    "limiting_speed_rpm": 530,
    "max_rpm": 530,
    "speed_oil_rpm": 750,
    "weight_g": 73400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 320 mm shaft position as 4T-323064UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 121 mm. Reading the designation: the last two digits 64 are the bore code, ×5 = 320 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. Axial capacity is bidirectional because the rows are opposed: 4T-323064UTG locates the shaft in both directions with C0 3100 kN behind the static check of the more heavily loaded row. The internal clearance of 4T-323064UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 121 mm overall width is the finished dimension. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-323064UTG are ground as a unit.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 320 mm bore the 4T-323064UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2030 kN C level.",
      "The 432 heavy plan gives 4T-323064UTG its 121 mm width and 2030 kN rating at the 320 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 247 kN Cu.",
      "The internal clearance of 4T-323064UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 2030 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Open 4T-323064UTG units have no seals: the housing must seal both rows or the 530 r/min grease figure is meaningless once contamination enters.",
      "The 2030/3100 kN ratings and 247 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323064UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323064UTG?",
        "a": "4T-323064UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 320 mm bore, 480 mm outside diameter and 121 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2030 kN, C0 3100 kN, Cu 247 kN, grease limiting speed 530 r/min, oil speed 750 r/min, mass about 73.4 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 320 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323064UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323064UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 121 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323064UTG mean?",
        "a": "Suffix reading on 323064UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323064UTG list two speeds, 530 and 750 r/min?",
        "a": "The lower figure, 530 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323064UTG at 750 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323064UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323064utg",
      "4t-323064utg",
      "＊323064utg",
      "323064UTG",
      "4T-323064UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413064UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413064UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 320,
    "D_mm": 480,
    "B_mm": 121,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1520,
    "static_load_kN": 2250,
    "fatigue_load_limit_kN": 181,
    "limiting_speed_rpm": 530,
    "max_rpm": 530,
    "speed_oil_rpm": 750,
    "weight_g": 69200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 320 mm shaft position as 4T-413064UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 121 mm. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 320 mm bore the 432 execution carries a wider, heavier section than the 430. Speed planning uses both catalogue columns: grease 530 r/min is the mechanical ceiling, oil 750 r/min with oil lubrication — a 220 r/min margin at this size. Because the unit is preset, mounting 4T-413064UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Mount 4T-413064UTG as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 320 mm bore the 4T-413064UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1520 kN C level.",
      "The 430 light plan keeps 4T-413064UTG narrower and faster than the 432 heavy execution of the same 320 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-413064UTG near 530 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 480 mm OD clamping uniformly around the circumference.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 121 mm width, load spread and clearance logic of 4T-413064UTG are unit-specific.",
      "The 1520/2250 kN ratings and 181 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413064UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413064UTG?",
        "a": "4T-413064UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 320 mm bore, 480 mm outside diameter and 121 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1520 kN, C0 2250 kN, Cu 181 kN, grease limiting speed 530 r/min, oil speed 750 r/min, mass about 69.2 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 320 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413064UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413064UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 121 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413064UTG mean?",
        "a": "Suffix reading on 413064UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413064UTG list two speeds, 530 and 750 r/min?",
        "a": "The lower figure, 530 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413064UTG at 750 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413064UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413064utg",
      "4t-413064utg",
      "＊413064utg",
      "413064UTG",
      "4T-413064UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423064UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423064UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 320,
    "D_mm": 480,
    "B_mm": 151,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2030,
    "static_load_kN": 3100,
    "fatigue_load_limit_kN": 247,
    "limiting_speed_rpm": 530,
    "max_rpm": 530,
    "speed_oil_rpm": 750,
    "weight_g": 82000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-423064UTG at 320 mm bore, 480 mm OD and 151 mm overall width, with a grease limiting speed of 530 r/min and an oil ceiling of 750 r/min. Unlike a pair of single-row bearings, the TDO unit of 4T-423064UTG integrates both rows in one article: the 151 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Axial capacity is bidirectional because the rows are opposed: 4T-423064UTG locates the shaft in both directions with C0 3100 kN behind the static check of the more heavily loaded row. Because the unit is preset, mounting 4T-423064UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-423064UTG; the double cup must seat square across its full 151 mm width.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 320 mm bore the 4T-423064UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2030 kN C level.",
      "The 430 light plan keeps 4T-423064UTG narrower and faster than the 432 heavy execution of the same 320 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Grease packs must leave free volume across the 151 mm width; over-greasing a unit churning near the 750 r/min oil-band speed raises temperature and expels the grease.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 480 mm OD clamping uniformly around the circumference.",
      "An unloaded 4T-423064UTG near 530 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 2030/3100 kN ratings and 247 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423064UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423064UTG?",
        "a": "4T-423064UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 320 mm bore, 480 mm outside diameter and 151 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2030 kN, C0 3100 kN, Cu 247 kN, grease limiting speed 530 r/min, oil speed 750 r/min, mass about 82 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 320 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423064UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423064UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 151 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423064UTG mean?",
        "a": "Suffix reading on 423064UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423064UTG list two speeds, 530 and 750 r/min?",
        "a": "The lower figure, 530 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423064UTG at 750 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423064UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423064utg",
      "4t-423064utg",
      "＊423064utg",
      "423064UTG",
      "4T-423064UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323164UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323164UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 320,
    "D_mm": 540,
    "B_mm": 176,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3200,
    "static_load_kN": 4900,
    "fatigue_load_limit_kN": 385,
    "limiting_speed_rpm": 500,
    "max_rpm": 500,
    "speed_oil_rpm": 710,
    "weight_g": 170000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 320 mm shaft position as 4T-323164UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 176 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-323164UTG integrates both rows in one article: the 176 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Axial capacity is bidirectional because the rows are opposed: 4T-323164UTG locates the shaft in both directions with C0 4900 kN behind the static check of the more heavily loaded row. Because the unit is preset, mounting 4T-323164UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 320 mm size before ordering 4T-323164UTG.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 320 mm bore the 4T-323164UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3200 kN C level.",
      "The 432 heavy plan gives 4T-323164UTG its 176 mm width and 3200 kN rating at the 320 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 385 kN Cu.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 540 mm OD clamping uniformly around the circumference.",
      "Grease packs must leave free volume across the 176 mm width; over-greasing a unit churning near the 710 r/min oil-band speed raises temperature and expels the grease.",
      "Order by the full 323164UTG code including suffixes — U, X, DX, E1 and UTG variants share the 320 mm bore but are different articles with different internal geometry.",
      "The 3200/4900 kN ratings and 385 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323164UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323164UTG?",
        "a": "4T-323164UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 320 mm bore, 540 mm outside diameter and 176 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3200 kN, C0 4900 kN, Cu 385 kN, grease limiting speed 500 r/min, oil speed 710 r/min, mass about 170 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 320 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323164UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323164UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 176 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323164UTG mean?",
        "a": "Suffix reading on 323164UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323164UTG list two speeds, 500 and 710 r/min?",
        "a": "The lower figure, 500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323164UTG at 710 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323164UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323164utg",
      "4t-323164utg",
      "＊323164utg",
      "323164UTG",
      "4T-323164UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413164UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413164UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 320,
    "D_mm": 540,
    "B_mm": 176,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2870,
    "static_load_kN": 4100,
    "fatigue_load_limit_kN": 320,
    "limiting_speed_rpm": 500,
    "max_rpm": 500,
    "speed_oil_rpm": 710,
    "weight_g": 150000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 320 mm shaft position as 4T-413164UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 176 mm. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 413164UTG reads accordingly. Selection: C 2870 kN against C0 4100 kN gives a C0/C ratio of 1.43; the two rows of 4T-413164UTG share the combined load as one bearing position. TDO construction means the two cone assemblies of 4T-413164UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 320 mm shaft. The open unit carries no seals; the housing of 4T-413164UTG must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 320 mm bore the 4T-413164UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2870 kN C level.",
      "The 430 light plan keeps 4T-413164UTG narrower and faster than the 432 heavy execution of the same 320 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Grease packs must leave free volume across the 176 mm width; over-greasing a unit churning near the 710 r/min oil-band speed raises temperature and expels the grease.",
      "The internal clearance of 4T-413164UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The internal clearance of 4T-413164UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 2870/4100 kN ratings and 320 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413164UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413164UTG?",
        "a": "4T-413164UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 320 mm bore, 540 mm outside diameter and 176 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2870 kN, C0 4100 kN, Cu 320 kN, grease limiting speed 500 r/min, oil speed 710 r/min, mass about 150 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 320 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413164UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413164UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 176 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413164UTG mean?",
        "a": "Suffix reading on 413164UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413164UTG list two speeds, 500 and 710 r/min?",
        "a": "The lower figure, 500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413164UTG at 710 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413164UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413164utg",
      "4t-413164utg",
      "＊413164utg",
      "413164UTG",
      "4T-413164UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423164UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423164UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 320,
    "D_mm": 540,
    "B_mm": 220,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3200,
    "static_load_kN": 4900,
    "fatigue_load_limit_kN": 385,
    "limiting_speed_rpm": 500,
    "max_rpm": 500,
    "speed_oil_rpm": 710,
    "weight_g": 190000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-423164UTG at 320 mm bore, 540 mm OD and 220 mm overall width, with a grease limiting speed of 500 r/min and an oil ceiling of 710 r/min. Suffix reading on 423164UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Axial capacity is bidirectional because the rows are opposed: 4T-423164UTG locates the shaft in both directions with C0 4900 kN behind the static check of the more heavily loaded row. TDO construction means the two cone assemblies of 4T-423164UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 320 mm shaft. Induction heating to max 120 °C is the standard fitting method at this 320 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 320 mm bore the 4T-423164UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3200 kN C level.",
      "The 430 light plan keeps 4T-423164UTG narrower and faster than the 432 heavy execution of the same 320 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 3200 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The internal clearance of 4T-423164UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "At inspection do not mix the cone assemblies of 4T-423164UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 3200/4900 kN ratings and 385 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423164UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423164UTG?",
        "a": "4T-423164UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 320 mm bore, 540 mm outside diameter and 220 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3200 kN, C0 4900 kN, Cu 385 kN, grease limiting speed 500 r/min, oil speed 710 r/min, mass about 190 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 320 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423164UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423164UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 220 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423164UTG mean?",
        "a": "Suffix reading on 423164UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423164UTG list two speeds, 500 and 710 r/min?",
        "a": "The lower figure, 500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423164UTG at 710 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423164UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423164utg",
      "4t-423164utg",
      "＊423164utg",
      "423164UTG",
      "4T-423164UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323068UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323068UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 340,
    "D_mm": 520,
    "B_mm": 133,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2420,
    "static_load_kN": 3750,
    "fatigue_load_limit_kN": 295,
    "limiting_speed_rpm": 490,
    "max_rpm": 490,
    "speed_oil_rpm": 700,
    "weight_g": 100000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-323068UTG denotes the heavy-duty 432-family TDO double-row series — a 340 mm bore double-row tapered unit rated 2420 kN basic dynamic and 3750 kN static. Suffix reading on 323068UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Selection: C 2420 kN against C0 3750 kN gives a C0/C ratio of 1.55; the two rows of 4T-323068UTG share the combined load as one bearing position. Because the unit is preset, mounting 4T-323068UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Induction heating to max 120 °C is the standard fitting method at this 340 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 340 mm bore the 4T-323068UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2420 kN C level.",
      "The 432 heavy plan gives 4T-323068UTG its 133 mm width and 2420 kN rating at the 340 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 295 kN Cu.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-323068UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 520 mm OD clamping uniformly around the circumference.",
      "Open 4T-323068UTG units have no seals: the housing must seal both rows or the 490 r/min grease figure is meaningless once contamination enters.",
      "The 2420/3750 kN ratings and 295 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323068UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323068UTG?",
        "a": "4T-323068UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 340 mm bore, 520 mm outside diameter and 133 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2420 kN, C0 3750 kN, Cu 295 kN, grease limiting speed 490 r/min, oil speed 700 r/min, mass about 100 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 340 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323068UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323068UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 133 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323068UTG mean?",
        "a": "Suffix reading on 323068UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323068UTG list two speeds, 490 and 700 r/min?",
        "a": "The lower figure, 490 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323068UTG at 700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323068UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323068utg",
      "4t-323068utg",
      "＊323068utg",
      "323068UTG",
      "4T-323068UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413068UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413068UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 340,
    "D_mm": 520,
    "B_mm": 133,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1890,
    "static_load_kN": 2870,
    "fatigue_load_limit_kN": 226,
    "limiting_speed_rpm": 500,
    "max_rpm": 500,
    "speed_oil_rpm": 700,
    "weight_g": 93100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-413068UTG denotes the light-duty 430-family TDO double-row series — a 340 mm bore double-row tapered unit rated 1890 kN basic dynamic and 2870 kN static. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 340 mm bore the 432 execution carries a wider, heavier section than the 430. Selection: C 1890 kN against C0 2870 kN gives a C0/C ratio of 1.52; the two rows of 4T-413068UTG share the combined load as one bearing position. The internal clearance of 4T-413068UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 133 mm overall width is the finished dimension. Mount 4T-413068UTG as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 340 mm bore the 4T-413068UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1890 kN C level.",
      "The 430 light plan keeps 4T-413068UTG narrower and faster than the 432 heavy execution of the same 340 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 90.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-413068UTG or the cones bottom out on the radius.",
      "The 90.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-413068UTG or the cones bottom out on the radius.",
      "The 90.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-413068UTG or the cones bottom out on the radius.",
      "The 1890/2870 kN ratings and 226 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413068UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413068UTG?",
        "a": "4T-413068UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 340 mm bore, 520 mm outside diameter and 133 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1890 kN, C0 2870 kN, Cu 226 kN, grease limiting speed 500 r/min, oil speed 700 r/min, mass about 93.1 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 340 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413068UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413068UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 133 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413068UTG mean?",
        "a": "Suffix reading on 413068UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413068UTG list two speeds, 500 and 700 r/min?",
        "a": "The lower figure, 500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413068UTG at 700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413068UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413068utg",
      "4t-413068utg",
      "＊413068utg",
      "413068UTG",
      "4T-413068UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423068UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423068UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 340,
    "D_mm": 520,
    "B_mm": 165,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2420,
    "static_load_kN": 3750,
    "fatigue_load_limit_kN": 295,
    "limiting_speed_rpm": 500,
    "max_rpm": 500,
    "speed_oil_rpm": 700,
    "weight_g": 110000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423068UTG is the NTN 4T catalogue entry for a 340×520×165 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 423068UTG reads accordingly. Selection: C 2420 kN against C0 3750 kN gives a C0/C ratio of 1.55; the two rows of 4T-423068UTG share the combined load as one bearing position. TDO construction means the two cone assemblies of 4T-423068UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 340 mm shaft. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-423068UTG are ground as a unit.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 340 mm bore the 4T-423068UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2420 kN C level.",
      "The 430 light plan keeps 4T-423068UTG narrower and faster than the 432 heavy execution of the same 340 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Open 4T-423068UTG units have no seals: the housing must seal both rows or the 500 r/min grease figure is meaningless once contamination enters.",
      "At inspection do not mix the cone assemblies of 4T-423068UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "An unloaded 4T-423068UTG near 500 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 2420/3750 kN ratings and 295 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423068UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423068UTG?",
        "a": "4T-423068UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 340 mm bore, 520 mm outside diameter and 165 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2420 kN, C0 3750 kN, Cu 295 kN, grease limiting speed 500 r/min, oil speed 700 r/min, mass about 110 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 340 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423068UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423068UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 165 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423068UTG mean?",
        "a": "Suffix reading on 423068UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423068UTG list two speeds, 500 and 700 r/min?",
        "a": "The lower figure, 500 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423068UTG at 700 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423068UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423068utg",
      "4t-423068utg",
      "＊423068utg",
      "423068UTG",
      "4T-423068UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323168UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323168UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 340,
    "D_mm": 580,
    "B_mm": 190,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 4300,
    "static_load_kN": 6500,
    "fatigue_load_limit_kN": 500,
    "limiting_speed_rpm": 460,
    "max_rpm": 460,
    "speed_oil_rpm": 660,
    "weight_g": 210000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-323168UTG denotes the heavy-duty 432-family TDO double-row series — a 340 mm bore double-row tapered unit rated 4300 kN basic dynamic and 6500 kN static. Unlike a pair of single-row bearings, the TDO unit of 4T-323168UTG integrates both rows in one article: the 190 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Grease relubrication at the 460 r/min limiting speed must reach both roller rows; sustaining 660 r/min needs an oil supply with defined flow through the double cup. TDO construction means the two cone assemblies of 4T-323168UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 340 mm shaft. With a rotating shaft a m6/n6 seat on the 340 mm journal and a located cup in the housing are typical practice for 4T-323168UTG.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 340 mm bore the 4T-323168UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 4300 kN C level.",
      "The 432 heavy plan gives 4T-323168UTG its 190 mm width and 4300 kN rating at the 340 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 500 kN Cu.",
      "The 4300 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The internal clearance of 4T-323168UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Order by the full 323168UTG code including suffixes — U, X, DX, E1 and UTG variants share the 340 mm bore but are different articles with different internal geometry.",
      "The 4300/6500 kN ratings and 500 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323168UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323168UTG?",
        "a": "4T-323168UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 340 mm bore, 580 mm outside diameter and 190 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 4300 kN, C0 6500 kN, Cu 500 kN, grease limiting speed 460 r/min, oil speed 660 r/min, mass about 210 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 340 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323168UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323168UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 190 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323168UTG mean?",
        "a": "Suffix reading on 323168UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323168UTG list two speeds, 460 and 660 r/min?",
        "a": "The lower figure, 460 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323168UTG at 660 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323168UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323168utg",
      "4t-323168utg",
      "＊323168utg",
      "323168UTG",
      "4T-323168UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413168UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413168UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 340,
    "D_mm": 580,
    "B_mm": 190,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3450,
    "static_load_kN": 4900,
    "fatigue_load_limit_kN": 380,
    "limiting_speed_rpm": 460,
    "max_rpm": 460,
    "speed_oil_rpm": 660,
    "weight_g": 190000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-413168UTG denotes the light-duty 430-family TDO double-row series — a 340 mm bore double-row tapered unit rated 3450 kN basic dynamic and 4900 kN static. Reading the designation: the last two digits 68 are the bore code, ×5 = 340 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. Selection: C 3450 kN against C0 4900 kN gives a C0/C ratio of 1.42; the two rows of 4T-413168UTG share the combined load as one bearing position. Because the unit is preset, mounting 4T-413168UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. The open unit carries no seals; the housing of 4T-413168UTG must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 340 mm bore the 4T-413168UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3450 kN C level.",
      "The 430 light plan keeps 4T-413168UTG narrower and faster than the 432 heavy execution of the same 340 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Open 4T-413168UTG units have no seals: the housing must seal both rows or the 460 r/min grease figure is meaningless once contamination enters.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 190 mm width, load spread and clearance logic of 4T-413168UTG are unit-specific.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 580 mm OD clamping uniformly around the circumference.",
      "The 3450/4900 kN ratings and 380 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413168UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413168UTG?",
        "a": "4T-413168UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 340 mm bore, 580 mm outside diameter and 190 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3450 kN, C0 4900 kN, Cu 380 kN, grease limiting speed 460 r/min, oil speed 660 r/min, mass about 190 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 340 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413168UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413168UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 190 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413168UTG mean?",
        "a": "Suffix reading on 413168UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413168UTG list two speeds, 460 and 660 r/min?",
        "a": "The lower figure, 460 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413168UTG at 660 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413168UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413168utg",
      "4t-413168utg",
      "＊413168utg",
      "413168UTG",
      "4T-413168UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423168UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423168UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 340,
    "D_mm": 580,
    "B_mm": 238,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 4300,
    "static_load_kN": 6500,
    "fatigue_load_limit_kN": 500,
    "limiting_speed_rpm": 460,
    "max_rpm": 460,
    "speed_oil_rpm": 660,
    "weight_g": 240000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423168UTG is the NTN 4T catalogue entry for a 340×580×238 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Suffix reading on 423168UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Grease relubrication at the 460 r/min limiting speed must reach both roller rows; sustaining 660 r/min needs an oil supply with defined flow through the double cup. The internal clearance of 4T-423168UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 238 mm overall width is the finished dimension. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 340 mm size before ordering 4T-423168UTG.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 340 mm bore the 4T-423168UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 4300 kN C level.",
      "The 430 light plan keeps 4T-423168UTG narrower and faster than the 432 heavy execution of the same 340 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-423168UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Order by the full 423168UTG code including suffixes — U, X, DX, E1 and UTG variants share the 340 mm bore but are different articles with different internal geometry.",
      "At inspection do not mix the cone assemblies of 4T-423168UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 4300/6500 kN ratings and 500 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423168UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423168UTG?",
        "a": "4T-423168UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 340 mm bore, 580 mm outside diameter and 238 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 4300 kN, C0 6500 kN, Cu 500 kN, grease limiting speed 460 r/min, oil speed 660 r/min, mass about 240 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 340 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423168UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423168UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 238 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423168UTG mean?",
        "a": "Suffix reading on 423168UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423168UTG list two speeds, 460 and 660 r/min?",
        "a": "The lower figure, 460 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423168UTG at 660 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423168UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=198",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423168utg",
      "4t-423168utg",
      "＊423168utg",
      "423168UTG",
      "4T-423168UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323072UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323072UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 360,
    "D_mm": 540,
    "B_mm": 134,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2630,
    "static_load_kN": 4200,
    "fatigue_load_limit_kN": 325,
    "limiting_speed_rpm": 460,
    "max_rpm": 460,
    "speed_oil_rpm": 660,
    "weight_g": 110000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323072UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 360×540×134 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-323072UTG integrates both rows in one article: the 134 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Speed planning uses both catalogue columns: grease 460 r/min is the mechanical ceiling, oil 660 r/min with oil lubrication — a 200 r/min margin at this size. The internal clearance of 4T-323072UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 134 mm overall width is the finished dimension. The open unit carries no seals; the housing of 4T-323072UTG must provide sealing and the grease fill or oil feed to both rows.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 360 mm bore the 4T-323072UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2630 kN C level.",
      "The 432 heavy plan gives 4T-323072UTG its 134 mm width and 2630 kN rating at the 360 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 325 kN Cu.",
      "Open 4T-323072UTG units have no seals: the housing must seal both rows or the 460 r/min grease figure is meaningless once contamination enters.",
      "At inspection do not mix the cone assemblies of 4T-323072UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Grease packs must leave free volume across the 134 mm width; over-greasing a unit churning near the 660 r/min oil-band speed raises temperature and expels the grease.",
      "The 2630/4200 kN ratings and 325 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323072UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323072UTG?",
        "a": "4T-323072UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 360 mm bore, 540 mm outside diameter and 134 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2630 kN, C0 4200 kN, Cu 325 kN, grease limiting speed 460 r/min, oil speed 660 r/min, mass about 110 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 360 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323072UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323072UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 134 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323072UTG mean?",
        "a": "Suffix reading on 323072UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323072UTG list two speeds, 460 and 660 r/min?",
        "a": "The lower figure, 460 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323072UTG at 660 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323072UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323072utg",
      "4t-323072utg",
      "＊323072utg",
      "323072UTG",
      "4T-323072UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413072UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413072UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 360,
    "D_mm": 540,
    "B_mm": 134,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 1880,
    "static_load_kN": 2810,
    "fatigue_load_limit_kN": 218,
    "limiting_speed_rpm": 460,
    "max_rpm": 460,
    "speed_oil_rpm": 660,
    "weight_g": 98200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413072UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 360×540×134 mm. Reading the designation: the last two digits 72 are the bore code, ×5 = 360 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. The 5.2 kN of dynamic capacity per millimetre of bore summarises the 1880 kN rating over the 360 mm bore — compare substitution candidates on this ratio and on the 134 mm width. Because the unit is preset, mounting 4T-413072UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Induction heating to max 120 °C is the standard fitting method at this 360 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 360 mm bore the 4T-413072UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 1880 kN C level.",
      "The 430 light plan keeps 4T-413072UTG narrower and faster than the 432 heavy execution of the same 360 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Order by the full 413072UTG code including suffixes — U, X, DX, E1 and UTG variants share the 360 mm bore but are different articles with different internal geometry.",
      "The 90.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-413072UTG or the cones bottom out on the radius.",
      "An unloaded 4T-413072UTG near 460 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 1880/2810 kN ratings and 218 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413072UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413072UTG?",
        "a": "4T-413072UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 360 mm bore, 540 mm outside diameter and 134 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 1880 kN, C0 2810 kN, Cu 218 kN, grease limiting speed 460 r/min, oil speed 660 r/min, mass about 98.2 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 360 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413072UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413072UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 134 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413072UTG mean?",
        "a": "Suffix reading on 413072UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413072UTG list two speeds, 460 and 660 r/min?",
        "a": "The lower figure, 460 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413072UTG at 660 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413072UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413072utg",
      "4t-413072utg",
      "＊413072utg",
      "413072UTG",
      "4T-413072UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423072UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423072UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 360,
    "D_mm": 540,
    "B_mm": 169,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2630,
    "static_load_kN": 4200,
    "fatigue_load_limit_kN": 325,
    "limiting_speed_rpm": 460,
    "max_rpm": 460,
    "speed_oil_rpm": 660,
    "weight_g": 120000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 360 mm shaft position as 4T-423072UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 169 mm. Suffix reading on 423072UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Speed planning uses both catalogue columns: grease 460 r/min is the mechanical ceiling, oil 660 r/min with oil lubrication — a 200 r/min margin at this size. Because the unit is preset, mounting 4T-423072UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-423072UTG's locating position.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 360 mm bore the 4T-423072UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2630 kN C level.",
      "The 430 light plan keeps 4T-423072UTG narrower and faster than the 432 heavy execution of the same 360 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 169 mm width, load spread and clearance logic of 4T-423072UTG are unit-specific.",
      "The 90.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-423072UTG or the cones bottom out on the radius.",
      "The 2630 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 2630/4200 kN ratings and 325 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423072UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423072UTG?",
        "a": "4T-423072UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 360 mm bore, 540 mm outside diameter and 169 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2630 kN, C0 4200 kN, Cu 325 kN, grease limiting speed 460 r/min, oil speed 660 r/min, mass about 120 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 360 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423072UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423072UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 169 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423072UTG mean?",
        "a": "Suffix reading on 423072UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423072UTG list two speeds, 460 and 660 r/min?",
        "a": "The lower figure, 460 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423072UTG at 660 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423072UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423072utg",
      "4t-423072utg",
      "＊423072utg",
      "423072UTG",
      "4T-423072UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323172UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323172UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 360,
    "D_mm": 600,
    "B_mm": 192,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 4100,
    "static_load_kN": 6500,
    "fatigue_load_limit_kN": 495,
    "limiting_speed_rpm": 430,
    "max_rpm": 430,
    "speed_oil_rpm": 620,
    "weight_g": 220000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 360 mm shaft needing a compact two-direction thrust location, NTN lists 4T-323172UTG, a TDO double-row 4T unit of 4100 kN C and 6500 kN C0 in the heavy-duty 432-family TDO double-row series. Suffix reading on 323172UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. The 120.0 mm radial section over the 360 mm bore carries two roller rows across the 192 mm width; abutment shoulders must clear both cone bores and the double-cup OD. TDO construction means the two cone assemblies of 4T-323172UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 360 mm shaft. At 4100 kN C the unit offers about 11.4 kN per millimetre of the 360 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 620 r/min.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 360 mm bore the 4T-323172UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 4100 kN C level.",
      "The 432 heavy plan gives 4T-323172UTG its 192 mm width and 4100 kN rating at the 360 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 495 kN Cu.",
      "An unloaded 4T-323172UTG near 430 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The internal clearance of 4T-323172UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "An unloaded 4T-323172UTG near 430 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 4100/6500 kN ratings and 495 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323172UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323172UTG?",
        "a": "4T-323172UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 360 mm bore, 600 mm outside diameter and 192 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 4100 kN, C0 6500 kN, Cu 495 kN, grease limiting speed 430 r/min, oil speed 620 r/min, mass about 220 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 360 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323172UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323172UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 192 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323172UTG mean?",
        "a": "Suffix reading on 323172UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323172UTG list two speeds, 430 and 620 r/min?",
        "a": "The lower figure, 430 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323172UTG at 620 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323172UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323172utg",
      "4t-323172utg",
      "＊323172utg",
      "323172UTG",
      "4T-323172UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413172UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413172UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 360,
    "D_mm": 600,
    "B_mm": 192,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3500,
    "static_load_kN": 5050,
    "fatigue_load_limit_kN": 385,
    "limiting_speed_rpm": 430,
    "max_rpm": 430,
    "speed_oil_rpm": 620,
    "weight_g": 200000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 360 mm shaft needing a compact two-direction thrust location, NTN lists 4T-413172UTG, a TDO double-row 4T unit of 3500 kN C and 5050 kN C0 in the light-duty 430-family TDO double-row series. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 360 mm bore the 432 execution carries a wider, heavier section than the 430. The 120.0 mm radial section over the 360 mm bore carries two roller rows across the 192 mm width; abutment shoulders must clear both cone bores and the double-cup OD. Because the unit is preset, mounting 4T-413172UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-413172UTG.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 360 mm bore the 4T-413172UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3500 kN C level.",
      "The 430 light plan keeps 4T-413172UTG narrower and faster than the 432 heavy execution of the same 360 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 192 mm width, load spread and clearance logic of 4T-413172UTG are unit-specific.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 192 mm width, load spread and clearance logic of 4T-413172UTG are unit-specific.",
      "Open 4T-413172UTG units have no seals: the housing must seal both rows or the 430 r/min grease figure is meaningless once contamination enters.",
      "The 3500/5050 kN ratings and 385 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413172UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413172UTG?",
        "a": "4T-413172UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 360 mm bore, 600 mm outside diameter and 192 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3500 kN, C0 5050 kN, Cu 385 kN, grease limiting speed 430 r/min, oil speed 620 r/min, mass about 200 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 360 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413172UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413172UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 192 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413172UTG mean?",
        "a": "Suffix reading on 413172UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413172UTG list two speeds, 430 and 620 r/min?",
        "a": "The lower figure, 430 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413172UTG at 620 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413172UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413172utg",
      "4t-413172utg",
      "＊413172utg",
      "413172UTG",
      "4T-413172UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423172UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423172UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 360,
    "D_mm": 600,
    "B_mm": 240,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 4100,
    "static_load_kN": 6500,
    "fatigue_load_limit_kN": 495,
    "limiting_speed_rpm": 430,
    "max_rpm": 430,
    "speed_oil_rpm": 620,
    "weight_g": 250000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423172UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 360×600×240 mm. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 423172UTG reads accordingly. The 120.0 mm radial section over the 360 mm bore carries two roller rows across the 240 mm width; abutment shoulders must clear both cone bores and the double-cup OD. The internal clearance of 4T-423172UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 240 mm overall width is the finished dimension. With a rotating shaft a m6/n6 seat on the 360 mm journal and a located cup in the housing are typical practice for 4T-423172UTG.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 360 mm bore the 4T-423172UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 4100 kN C level.",
      "The 430 light plan keeps 4T-423172UTG narrower and faster than the 432 heavy execution of the same 360 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 120.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-423172UTG or the cones bottom out on the radius.",
      "Order by the full 423172UTG code including suffixes — U, X, DX, E1 and UTG variants share the 360 mm bore but are different articles with different internal geometry.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-423172UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 4100/6500 kN ratings and 495 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423172UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423172UTG?",
        "a": "4T-423172UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 360 mm bore, 600 mm outside diameter and 240 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 4100 kN, C0 6500 kN, Cu 495 kN, grease limiting speed 430 r/min, oil speed 620 r/min, mass about 250 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 360 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423172UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423172UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 240 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423172UTG mean?",
        "a": "Suffix reading on 423172UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423172UTG list two speeds, 430 and 620 r/min?",
        "a": "The lower figure, 430 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423172UTG at 620 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423172UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423172utg",
      "4t-423172utg",
      "＊423172utg",
      "423172UTG",
      "4T-423172UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323076",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323076",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 380,
    "D_mm": 560,
    "B_mm": 135,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2310,
    "static_load_kN": 4350,
    "fatigue_load_limit_kN": 335,
    "limiting_speed_rpm": 440,
    "max_rpm": 440,
    "speed_oil_rpm": 580,
    "weight_g": 110000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323076 belongs to the heavy-duty 432-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. With no letter suffix, 323076 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code. Double-row capacity is not twice a single-row bearing: the printed 2310 kN C already accounts for load sharing between the two rows of 4T-323076, so apply it directly in the L10 calculation. TDO construction means the two cone assemblies of 4T-323076 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 380 mm shaft. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-323076 are ground as a unit.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 380 mm bore the 4T-323076 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2310 kN C level.",
      "The 432 heavy plan gives 4T-323076 its 135 mm width and 2310 kN rating at the 380 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 335 kN Cu.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-323076 feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-323076 feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The internal clearance of 4T-323076 is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 2310/4350 kN ratings and 335 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323076; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323076?",
        "a": "4T-323076 is a double-row tapered roller bearing of TDO (back-to-back) construction: 380 mm bore, 560 mm outside diameter and 135 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2310 kN, C0 4350 kN, Cu 335 kN, grease limiting speed 440 r/min, oil speed 580 r/min, mass about 110 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 380 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323076 belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323076 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 135 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323076 mean?",
        "a": "With no letter suffix, 323076 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-323076 list two speeds, 440 and 580 r/min?",
        "a": "The lower figure, 440 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323076 at 580 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323076",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-323076",
      "323076",
      "4T-323076"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413076UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413076UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 380,
    "D_mm": 560,
    "B_mm": 135,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2170,
    "static_load_kN": 3350,
    "fatigue_load_limit_kN": 255,
    "limiting_speed_rpm": 440,
    "max_rpm": 440,
    "speed_oil_rpm": 620,
    "weight_g": 100000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413076UTG belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Suffix reading on 413076UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. The 5.7 kN of dynamic capacity per millimetre of bore summarises the 2170 kN rating over the 380 mm bore — compare substitution candidates on this ratio and on the 135 mm width. The internal clearance of 4T-413076UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 135 mm overall width is the finished dimension. Induction heating to max 120 °C is the standard fitting method at this 380 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 380 mm bore the 4T-413076UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2170 kN C level.",
      "The 430 light plan keeps 4T-413076UTG narrower and faster than the 432 heavy execution of the same 380 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 2170 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Grease packs must leave free volume across the 135 mm width; over-greasing a unit churning near the 620 r/min oil-band speed raises temperature and expels the grease.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-413076UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 2170/3350 kN ratings and 255 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413076UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413076UTG?",
        "a": "4T-413076UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 380 mm bore, 560 mm outside diameter and 135 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2170 kN, C0 3350 kN, Cu 255 kN, grease limiting speed 440 r/min, oil speed 620 r/min, mass about 100 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 380 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413076UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413076UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 135 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413076UTG mean?",
        "a": "Suffix reading on 413076UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413076UTG list two speeds, 440 and 620 r/min?",
        "a": "The lower figure, 440 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413076UTG at 620 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413076UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413076utg",
      "4t-413076utg",
      "＊413076utg",
      "413076UTG",
      "4T-413076UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423076UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423076UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 380,
    "D_mm": 560,
    "B_mm": 171,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2670,
    "static_load_kN": 4350,
    "fatigue_load_limit_kN": 335,
    "limiting_speed_rpm": 440,
    "max_rpm": 440,
    "speed_oil_rpm": 620,
    "weight_g": 130000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423076UTG belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 380 mm bore the 432 execution carries a wider, heavier section than the 430. The 90.0 mm radial section over the 380 mm bore carries two roller rows across the 171 mm width; abutment shoulders must clear both cone bores and the double-cup OD. Because the unit is preset, mounting 4T-423076UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Induction heating to max 120 °C is the standard fitting method at this 380 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 380 mm bore the 4T-423076UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2670 kN C level.",
      "The 430 light plan keeps 4T-423076UTG narrower and faster than the 432 heavy execution of the same 380 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 560 mm OD clamping uniformly around the circumference.",
      "An unloaded 4T-423076UTG near 440 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Order by the full 423076UTG code including suffixes — U, X, DX, E1 and UTG variants share the 380 mm bore but are different articles with different internal geometry.",
      "The 2670/4350 kN ratings and 335 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423076UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423076UTG?",
        "a": "4T-423076UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 380 mm bore, 560 mm outside diameter and 171 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2670 kN, C0 4350 kN, Cu 335 kN, grease limiting speed 440 r/min, oil speed 620 r/min, mass about 130 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 380 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423076UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423076UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 171 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423076UTG mean?",
        "a": "Suffix reading on 423076UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423076UTG list two speeds, 440 and 620 r/min?",
        "a": "The lower figure, 440 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423076UTG at 620 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423076UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423076utg",
      "4t-423076utg",
      "＊423076utg",
      "423076UTG",
      "4T-423076UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323176",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323176",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 380,
    "D_mm": 620,
    "B_mm": 194,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3700,
    "static_load_kN": 6700,
    "fatigue_load_limit_kN": 505,
    "limiting_speed_rpm": 410,
    "max_rpm": 410,
    "speed_oil_rpm": 540,
    "weight_g": 230000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-323176 denotes the heavy-duty 432-family TDO double-row series — a 380 mm bore double-row tapered unit rated 3700 kN basic dynamic and 6700 kN static. Unlike a pair of single-row bearings, the TDO unit of 4T-323176 integrates both rows in one article: the 194 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The fatigue load limit Cu printed for 4T-323176 is 505 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-323176 face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 380 mm shaft. Mount 4T-323176 as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 380 mm bore the 4T-323176 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3700 kN C level.",
      "The 432 heavy plan gives 4T-323176 its 194 mm width and 3700 kN rating at the 380 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 505 kN Cu.",
      "Open 4T-323176 units have no seals: the housing must seal both rows or the 410 r/min grease figure is meaningless once contamination enters.",
      "The 3700 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Grease packs must leave free volume across the 194 mm width; over-greasing a unit churning near the 540 r/min oil-band speed raises temperature and expels the grease.",
      "The 3700/6700 kN ratings and 505 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323176; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323176?",
        "a": "4T-323176 is a double-row tapered roller bearing of TDO (back-to-back) construction: 380 mm bore, 620 mm outside diameter and 194 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3700 kN, C0 6700 kN, Cu 505 kN, grease limiting speed 410 r/min, oil speed 540 r/min, mass about 230 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 380 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323176 belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323176 be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 194 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323176 mean?",
        "a": "With no letter suffix, 323176 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code."
      },
      {
        "q": "Why does 4T-323176 list two speeds, 410 and 540 r/min?",
        "a": "The lower figure, 410 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323176 at 540 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323176",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4t-323176",
      "323176",
      "4T-323176"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413176UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413176UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 380,
    "D_mm": 620,
    "B_mm": 194,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3650,
    "static_load_kN": 5250,
    "fatigue_load_limit_kN": 395,
    "limiting_speed_rpm": 410,
    "max_rpm": 410,
    "speed_oil_rpm": 580,
    "weight_g": 210000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-413176UTG at 380 mm bore, 620 mm OD and 194 mm overall width, with a grease limiting speed of 410 r/min and an oil ceiling of 580 r/min. Unlike a pair of single-row bearings, the TDO unit of 4T-413176UTG integrates both rows in one article: the 194 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Catalogue mass of 4T-413176UTG is 210 kg; lifting and fitting tackle must be rated for the whole preset unit, not for single-ring handling. TDO construction means the two cone assemblies of 4T-413176UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 380 mm shaft. Axial clamping of the double cup must be uniform around the 620 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 380 mm bore the 4T-413176UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3650 kN C level.",
      "The 430 light plan keeps 4T-413176UTG narrower and faster than the 432 heavy execution of the same 380 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 620 mm OD clamping uniformly around the circumference.",
      "Open 4T-413176UTG units have no seals: the housing must seal both rows or the 410 r/min grease figure is meaningless once contamination enters.",
      "Open 4T-413176UTG units have no seals: the housing must seal both rows or the 410 r/min grease figure is meaningless once contamination enters.",
      "The 3650/5250 kN ratings and 395 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413176UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413176UTG?",
        "a": "4T-413176UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 380 mm bore, 620 mm outside diameter and 194 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3650 kN, C0 5250 kN, Cu 395 kN, grease limiting speed 410 r/min, oil speed 580 r/min, mass about 210 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 380 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413176UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413176UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 194 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413176UTG mean?",
        "a": "Suffix reading on 413176UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413176UTG list two speeds, 410 and 580 r/min?",
        "a": "The lower figure, 410 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413176UTG at 580 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413176UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413176utg",
      "4t-413176utg",
      "＊413176utg",
      "413176UTG",
      "4T-413176UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423176UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423176UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 380,
    "D_mm": 620,
    "B_mm": 243,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 4250,
    "static_load_kN": 6700,
    "fatigue_load_limit_kN": 505,
    "limiting_speed_rpm": 410,
    "max_rpm": 410,
    "speed_oil_rpm": 580,
    "weight_g": 260000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423176UTG belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Reading the designation: the last two digits 76 are the bore code, ×5 = 380 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. The 120.0 mm radial section over the 380 mm bore carries two roller rows across the 243 mm width; abutment shoulders must clear both cone bores and the double-cup OD. TDO construction means the two cone assemblies of 4T-423176UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 380 mm shaft. With a rotating shaft a m6/n6 seat on the 380 mm journal and a located cup in the housing are typical practice for 4T-423176UTG.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 380 mm bore the 4T-423176UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 4250 kN C level.",
      "The 430 light plan keeps 4T-423176UTG narrower and faster than the 432 heavy execution of the same 380 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Order by the full 423176UTG code including suffixes — U, X, DX, E1 and UTG variants share the 380 mm bore but are different articles with different internal geometry.",
      "Open 4T-423176UTG units have no seals: the housing must seal both rows or the 410 r/min grease figure is meaningless once contamination enters.",
      "Grease packs must leave free volume across the 243 mm width; over-greasing a unit churning near the 580 r/min oil-band speed raises temperature and expels the grease.",
      "The 4250/6700 kN ratings and 505 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423176UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423176UTG?",
        "a": "4T-423176UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 380 mm bore, 620 mm outside diameter and 243 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 4250 kN, C0 6700 kN, Cu 505 kN, grease limiting speed 410 r/min, oil speed 580 r/min, mass about 260 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 380 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423176UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423176UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 243 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423176UTG mean?",
        "a": "Suffix reading on 423176UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423176UTG list two speeds, 410 and 580 r/min?",
        "a": "The lower figure, 410 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423176UTG at 580 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423176UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423176utg",
      "4t-423176utg",
      "＊423176utg",
      "423176UTG",
      "4T-423176UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323080UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323080UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 400,
    "D_mm": 600,
    "B_mm": 148,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3250,
    "static_load_kN": 5450,
    "fatigue_load_limit_kN": 410,
    "limiting_speed_rpm": 410,
    "max_rpm": 410,
    "speed_oil_rpm": 580,
    "weight_g": 150000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323080UTG is the NTN 4T catalogue entry for a 400×600×148 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 400 mm bore the 432 execution carries a wider, heavier section than the 430. Axial capacity is bidirectional because the rows are opposed: 4T-323080UTG locates the shaft in both directions with C0 5450 kN behind the static check of the more heavily loaded row. Because the unit is preset, mounting 4T-323080UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Axial clamping of the double cup must be uniform around the 600 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 400 mm bore the 4T-323080UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3250 kN C level.",
      "The 432 heavy plan gives 4T-323080UTG its 148 mm width and 3250 kN rating at the 400 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 410 kN Cu.",
      "The internal clearance of 4T-323080UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 100.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-323080UTG or the cones bottom out on the radius.",
      "At inspection do not mix the cone assemblies of 4T-323080UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 3250/5450 kN ratings and 410 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323080UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323080UTG?",
        "a": "4T-323080UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 400 mm bore, 600 mm outside diameter and 148 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3250 kN, C0 5450 kN, Cu 410 kN, grease limiting speed 410 r/min, oil speed 580 r/min, mass about 150 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 400 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323080UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323080UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 148 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323080UTG mean?",
        "a": "Suffix reading on 323080UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323080UTG list two speeds, 410 and 580 r/min?",
        "a": "The lower figure, 410 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323080UTG at 580 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323080UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323080utg",
      "4t-323080utg",
      "＊323080utg",
      "323080UTG",
      "4T-323080UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413080UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413080UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 400,
    "D_mm": 600,
    "B_mm": 148,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2390,
    "static_load_kN": 3700,
    "fatigue_load_limit_kN": 276,
    "limiting_speed_rpm": 410,
    "max_rpm": 410,
    "speed_oil_rpm": 580,
    "weight_g": 130000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413080UTG is the NTN 4T catalogue entry for a 400×600×148 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Unlike a pair of single-row bearings, the TDO unit of 4T-413080UTG integrates both rows in one article: the 148 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Axial capacity is bidirectional because the rows are opposed: 4T-413080UTG locates the shaft in both directions with C0 3700 kN behind the static check of the more heavily loaded row. The internal clearance of 4T-413080UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 148 mm overall width is the finished dimension. The preset clearance suits the standard temperature range; unusual thermal gradients between shaft and housing call for a clearance review against the 400 mm size before ordering 4T-413080UTG.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 400 mm bore the 4T-413080UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2390 kN C level.",
      "The 430 light plan keeps 4T-413080UTG narrower and faster than the 432 heavy execution of the same 400 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-413080UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Grease packs must leave free volume across the 148 mm width; over-greasing a unit churning near the 580 r/min oil-band speed raises temperature and expels the grease.",
      "Order by the full 413080UTG code including suffixes — U, X, DX, E1 and UTG variants share the 400 mm bore but are different articles with different internal geometry.",
      "The 2390/3700 kN ratings and 276 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413080UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413080UTG?",
        "a": "4T-413080UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 400 mm bore, 600 mm outside diameter and 148 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2390 kN, C0 3700 kN, Cu 276 kN, grease limiting speed 410 r/min, oil speed 580 r/min, mass about 130 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 400 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413080UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413080UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 148 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413080UTG mean?",
        "a": "Suffix reading on 413080UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413080UTG list two speeds, 410 and 580 r/min?",
        "a": "The lower figure, 410 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413080UTG at 580 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413080UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413080utg",
      "4t-413080utg",
      "＊413080utg",
      "413080UTG",
      "4T-413080UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423080UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423080UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 400,
    "D_mm": 600,
    "B_mm": 185,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3250,
    "static_load_kN": 5450,
    "fatigue_load_limit_kN": 410,
    "limiting_speed_rpm": 410,
    "max_rpm": 410,
    "speed_oil_rpm": 580,
    "weight_g": 170000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 400 mm shaft needing a compact two-direction thrust location, NTN lists 4T-423080UTG, a TDO double-row 4T unit of 3250 kN C and 5450 kN C0 in the light-duty 430-family TDO double-row series. Reading the designation: the last two digits 80 are the bore code, ×5 = 400 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. Axial capacity is bidirectional because the rows are opposed: 4T-423080UTG locates the shaft in both directions with C0 5450 kN behind the static check of the more heavily loaded row. TDO construction means the two cone assemblies of 4T-423080UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 400 mm shaft. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-423080UTG.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 400 mm bore the 4T-423080UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3250 kN C level.",
      "The 430 light plan keeps 4T-423080UTG narrower and faster than the 432 heavy execution of the same 400 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Grease packs must leave free volume across the 185 mm width; over-greasing a unit churning near the 580 r/min oil-band speed raises temperature and expels the grease.",
      "An unloaded 4T-423080UTG near 410 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 185 mm width, load spread and clearance logic of 4T-423080UTG are unit-specific.",
      "The 3250/5450 kN ratings and 410 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423080UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423080UTG?",
        "a": "4T-423080UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 400 mm bore, 600 mm outside diameter and 185 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3250 kN, C0 5450 kN, Cu 410 kN, grease limiting speed 410 r/min, oil speed 580 r/min, mass about 170 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 400 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423080UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423080UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 185 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423080UTG mean?",
        "a": "Suffix reading on 423080UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423080UTG list two speeds, 410 and 580 r/min?",
        "a": "The lower figure, 410 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423080UTG at 580 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423080UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423080utg",
      "4t-423080utg",
      "＊423080utg",
      "423080UTG",
      "4T-423080UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323180UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323180UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 400,
    "D_mm": 650,
    "B_mm": 200,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 4800,
    "static_load_kN": 7850,
    "fatigue_load_limit_kN": 580,
    "limiting_speed_rpm": 380,
    "max_rpm": 380,
    "speed_oil_rpm": 540,
    "weight_g": 260000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323180UTG is the NTN 4T catalogue entry for a 400×650×200 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 323180UTG reads accordingly. Double-row capacity is not twice a single-row bearing: the printed 4800 kN C already accounts for load sharing between the two rows of 4T-323180UTG, so apply it directly in the L10 calculation. TDO construction means the two cone assemblies of 4T-323180UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 400 mm shaft. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-323180UTG are ground as a unit.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 400 mm bore the 4T-323180UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 4800 kN C level.",
      "The 432 heavy plan gives 4T-323180UTG its 200 mm width and 4800 kN rating at the 400 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 580 kN Cu.",
      "Order by the full 323180UTG code including suffixes — U, X, DX, E1 and UTG variants share the 400 mm bore but are different articles with different internal geometry.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 200 mm width, load spread and clearance logic of 4T-323180UTG are unit-specific.",
      "The 4800 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 4800/7850 kN ratings and 580 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323180UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323180UTG?",
        "a": "4T-323180UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 400 mm bore, 650 mm outside diameter and 200 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 4800 kN, C0 7850 kN, Cu 580 kN, grease limiting speed 380 r/min, oil speed 540 r/min, mass about 260 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 400 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323180UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323180UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 200 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323180UTG mean?",
        "a": "Suffix reading on 323180UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323180UTG list two speeds, 380 and 540 r/min?",
        "a": "The lower figure, 380 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323180UTG at 540 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323180UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323180utg",
      "4t-323180utg",
      "＊323180utg",
      "323180UTG",
      "4T-323180UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413180UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413180UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 400,
    "D_mm": 650,
    "B_mm": 200,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3850,
    "static_load_kN": 5800,
    "fatigue_load_limit_kN": 430,
    "limiting_speed_rpm": 380,
    "max_rpm": 380,
    "speed_oil_rpm": 540,
    "weight_g": 240000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413180UTG is the NTN 4T catalogue entry for a 400×650×200 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Suffix reading on 413180UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Axial capacity is bidirectional because the rows are opposed: 4T-413180UTG locates the shaft in both directions with C0 5800 kN behind the static check of the more heavily loaded row. Because the unit is preset, mounting 4T-413180UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. At 3850 kN C the unit offers about 9.6 kN per millimetre of the 400 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 540 r/min.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 400 mm bore the 4T-413180UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3850 kN C level.",
      "The 430 light plan keeps 4T-413180UTG narrower and faster than the 432 heavy execution of the same 400 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Grease packs must leave free volume across the 200 mm width; over-greasing a unit churning near the 540 r/min oil-band speed raises temperature and expels the grease.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-413180UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Grease packs must leave free volume across the 200 mm width; over-greasing a unit churning near the 540 r/min oil-band speed raises temperature and expels the grease.",
      "The 3850/5800 kN ratings and 430 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413180UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413180UTG?",
        "a": "4T-413180UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 400 mm bore, 650 mm outside diameter and 200 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3850 kN, C0 5800 kN, Cu 430 kN, grease limiting speed 380 r/min, oil speed 540 r/min, mass about 240 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 400 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413180UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413180UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 200 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413180UTG mean?",
        "a": "Suffix reading on 413180UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413180UTG list two speeds, 380 and 540 r/min?",
        "a": "The lower figure, 380 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413180UTG at 540 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413180UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413180utg",
      "4t-413180utg",
      "＊413180utg",
      "413180UTG",
      "4T-413180UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423180UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423180UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 400,
    "D_mm": 650,
    "B_mm": 250,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 4800,
    "static_load_kN": 7850,
    "fatigue_load_limit_kN": 580,
    "limiting_speed_rpm": 380,
    "max_rpm": 380,
    "speed_oil_rpm": 540,
    "weight_g": 290000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 400 mm shaft needing a compact two-direction thrust location, NTN lists 4T-423180UTG, a TDO double-row 4T unit of 4800 kN C and 7850 kN C0 in the light-duty 430-family TDO double-row series. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 400 mm bore the 432 execution carries a wider, heavier section than the 430. Double-row capacity is not twice a single-row bearing: the printed 4800 kN C already accounts for load sharing between the two rows of 4T-423180UTG, so apply it directly in the L10 calculation. The internal clearance of 4T-423180UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 250 mm overall width is the finished dimension. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-423180UTG; the double cup must seat square across its full 250 mm width.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 400 mm bore the 4T-423180UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 4800 kN C level.",
      "The 430 light plan keeps 4T-423180UTG narrower and faster than the 432 heavy execution of the same 400 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The internal clearance of 4T-423180UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Open 4T-423180UTG units have no seals: the housing must seal both rows or the 380 r/min grease figure is meaningless once contamination enters.",
      "The internal clearance of 4T-423180UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 4800/7850 kN ratings and 580 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423180UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423180UTG?",
        "a": "4T-423180UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 400 mm bore, 650 mm outside diameter and 250 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 4800 kN, C0 7850 kN, Cu 580 kN, grease limiting speed 380 r/min, oil speed 540 r/min, mass about 290 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 400 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423180UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423180UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 250 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423180UTG mean?",
        "a": "Suffix reading on 423180UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423180UTG list two speeds, 380 and 540 r/min?",
        "a": "The lower figure, 380 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423180UTG at 540 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423180UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423180utg",
      "4t-423180utg",
      "＊423180utg",
      "423180UTG",
      "4T-423180UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323084UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323084UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 420,
    "D_mm": 620,
    "B_mm": 150,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3400,
    "static_load_kN": 5900,
    "fatigue_load_limit_kN": 435,
    "limiting_speed_rpm": 390,
    "max_rpm": 390,
    "speed_oil_rpm": 550,
    "weight_g": 150000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 420 mm shaft position as 4T-323084UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 150 mm. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 420 mm bore the 432 execution carries a wider, heavier section than the 430. Double-row capacity is not twice a single-row bearing: the printed 3400 kN C already accounts for load sharing between the two rows of 4T-323084UTG, so apply it directly in the L10 calculation. The internal clearance of 4T-323084UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 150 mm overall width is the finished dimension. Axial clamping of the double cup must be uniform around the 620 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 420 mm bore the 4T-323084UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3400 kN C level.",
      "The 432 heavy plan gives 4T-323084UTG its 150 mm width and 3400 kN rating at the 420 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 435 kN Cu.",
      "Grease packs must leave free volume across the 150 mm width; over-greasing a unit churning near the 550 r/min oil-band speed raises temperature and expels the grease.",
      "Grease packs must leave free volume across the 150 mm width; over-greasing a unit churning near the 550 r/min oil-band speed raises temperature and expels the grease.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 150 mm width, load spread and clearance logic of 4T-323084UTG are unit-specific.",
      "The 3400/5900 kN ratings and 435 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323084UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323084UTG?",
        "a": "4T-323084UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 420 mm bore, 620 mm outside diameter and 150 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3400 kN, C0 5900 kN, Cu 435 kN, grease limiting speed 390 r/min, oil speed 550 r/min, mass about 150 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 420 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323084UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323084UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 150 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323084UTG mean?",
        "a": "Suffix reading on 323084UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323084UTG list two speeds, 390 and 550 r/min?",
        "a": "The lower figure, 390 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323084UTG at 550 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323084UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323084utg",
      "4t-323084utg",
      "＊323084utg",
      "323084UTG",
      "4T-323084UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413084UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413084UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 420,
    "D_mm": 620,
    "B_mm": 150,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 2710,
    "static_load_kN": 4250,
    "fatigue_load_limit_kN": 315,
    "limiting_speed_rpm": 390,
    "max_rpm": 390,
    "speed_oil_rpm": 550,
    "weight_g": 140000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 420 mm shaft position as 4T-413084UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 150 mm. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 413084UTG reads accordingly. Selection: C 2710 kN against C0 4250 kN gives a C0/C ratio of 1.57; the two rows of 4T-413084UTG share the combined load as one bearing position. Because the unit is preset, mounting 4T-413084UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. With a rotating shaft a m6/n6 seat on the 420 mm journal and a located cup in the housing are typical practice for 4T-413084UTG.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 420 mm bore the 4T-413084UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 2710 kN C level.",
      "The 430 light plan keeps 4T-413084UTG narrower and faster than the 432 heavy execution of the same 420 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 100.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-413084UTG or the cones bottom out on the radius.",
      "The internal clearance of 4T-413084UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Order by the full 413084UTG code including suffixes — U, X, DX, E1 and UTG variants share the 420 mm bore but are different articles with different internal geometry.",
      "The 2710/4250 kN ratings and 315 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413084UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413084UTG?",
        "a": "4T-413084UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 420 mm bore, 620 mm outside diameter and 150 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 2710 kN, C0 4250 kN, Cu 315 kN, grease limiting speed 390 r/min, oil speed 550 r/min, mass about 140 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 420 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413084UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413084UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 150 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413084UTG mean?",
        "a": "Suffix reading on 413084UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413084UTG list two speeds, 390 and 550 r/min?",
        "a": "The lower figure, 390 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413084UTG at 550 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413084UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413084utg",
      "4t-413084utg",
      "＊413084utg",
      "413084UTG",
      "4T-413084UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423084UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423084UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 420,
    "D_mm": 620,
    "B_mm": 188,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3400,
    "static_load_kN": 5900,
    "fatigue_load_limit_kN": 435,
    "limiting_speed_rpm": 390,
    "max_rpm": 390,
    "speed_oil_rpm": 550,
    "weight_g": 180000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-423084UTG at 420 mm bore, 620 mm OD and 188 mm overall width, with a grease limiting speed of 390 r/min and an oil ceiling of 550 r/min. Reading the designation: the last two digits 84 are the bore code, ×5 = 420 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. Double-row capacity is not twice a single-row bearing: the printed 3400 kN C already accounts for load sharing between the two rows of 4T-423084UTG, so apply it directly in the L10 calculation. Because the unit is preset, mounting 4T-423084UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-423084UTG.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 420 mm bore the 4T-423084UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3400 kN C level.",
      "The 430 light plan keeps 4T-423084UTG narrower and faster than the 432 heavy execution of the same 420 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-423084UTG near 390 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The internal clearance of 4T-423084UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 100.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-423084UTG or the cones bottom out on the radius.",
      "The 3400/5900 kN ratings and 435 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423084UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423084UTG?",
        "a": "4T-423084UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 420 mm bore, 620 mm outside diameter and 188 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3400 kN, C0 5900 kN, Cu 435 kN, grease limiting speed 390 r/min, oil speed 550 r/min, mass about 180 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 420 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423084UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423084UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 188 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423084UTG mean?",
        "a": "Suffix reading on 423084UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423084UTG list two speeds, 390 and 550 r/min?",
        "a": "The lower figure, 390 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423084UTG at 550 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423084UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423084utg",
      "4t-423084utg",
      "＊423084utg",
      "423084UTG",
      "4T-423084UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323184UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323184UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 420,
    "D_mm": 700,
    "B_mm": 224,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 6150,
    "static_load_kN": 9700,
    "fatigue_load_limit_kN": 705,
    "limiting_speed_rpm": 360,
    "max_rpm": 360,
    "speed_oil_rpm": 510,
    "weight_g": 350000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 420 mm shaft position as 4T-323184UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 224 mm. Reading the designation: the last two digits 84 are the bore code, ×5 = 420 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the heavy-duty 432-family TDO double-row series. Double-row capacity is not twice a single-row bearing: the printed 6150 kN C already accounts for load sharing between the two rows of 4T-323184UTG, so apply it directly in the L10 calculation. Because the unit is preset, mounting 4T-323184UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-323184UTG are ground as a unit.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 420 mm bore the 4T-323184UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 6150 kN C level.",
      "The 432 heavy plan gives 4T-323184UTG its 224 mm width and 6150 kN rating at the 420 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 705 kN Cu.",
      "The 6150 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-323184UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The internal clearance of 4T-323184UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 6150/9700 kN ratings and 705 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323184UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323184UTG?",
        "a": "4T-323184UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 420 mm bore, 700 mm outside diameter and 224 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 6150 kN, C0 9700 kN, Cu 705 kN, grease limiting speed 360 r/min, oil speed 510 r/min, mass about 350 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 420 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323184UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323184UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 224 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323184UTG mean?",
        "a": "Suffix reading on 323184UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323184UTG list two speeds, 360 and 510 r/min?",
        "a": "The lower figure, 360 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323184UTG at 510 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323184UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323184utg",
      "4t-323184utg",
      "＊323184utg",
      "323184UTG",
      "4T-323184UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413184UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413184UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 420,
    "D_mm": 700,
    "B_mm": 224,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 4750,
    "static_load_kN": 7200,
    "fatigue_load_limit_kN": 525,
    "limiting_speed_rpm": 360,
    "max_rpm": 360,
    "speed_oil_rpm": 510,
    "weight_g": 320000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 420 mm shaft position as 4T-413184UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 224 mm. Suffix reading on 413184UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Grease relubrication at the 360 r/min limiting speed must reach both roller rows; sustaining 510 r/min needs an oil supply with defined flow through the double cup. TDO construction means the two cone assemblies of 4T-413184UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 420 mm shaft. Mount 4T-413184UTG as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 420 mm bore the 4T-413184UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 4750 kN C level.",
      "The 430 light plan keeps 4T-413184UTG narrower and faster than the 432 heavy execution of the same 420 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-413184UTG near 360 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 4750 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Grease packs must leave free volume across the 224 mm width; over-greasing a unit churning near the 510 r/min oil-band speed raises temperature and expels the grease.",
      "The 4750/7200 kN ratings and 525 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413184UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413184UTG?",
        "a": "4T-413184UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 420 mm bore, 700 mm outside diameter and 224 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 4750 kN, C0 7200 kN, Cu 525 kN, grease limiting speed 360 r/min, oil speed 510 r/min, mass about 320 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 420 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413184UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413184UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 224 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413184UTG mean?",
        "a": "Suffix reading on 413184UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413184UTG list two speeds, 360 and 510 r/min?",
        "a": "The lower figure, 360 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413184UTG at 510 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413184UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413184utg",
      "4t-413184utg",
      "＊413184utg",
      "413184UTG",
      "4T-413184UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423184UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423184UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 420,
    "D_mm": 700,
    "B_mm": 280,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 6150,
    "static_load_kN": 9700,
    "fatigue_load_limit_kN": 705,
    "limiting_speed_rpm": 360,
    "max_rpm": 360,
    "speed_oil_rpm": 510,
    "weight_g": 380000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-423184UTG at 420 mm bore, 700 mm OD and 280 mm overall width, with a grease limiting speed of 360 r/min and an oil ceiling of 510 r/min. Unlike a pair of single-row bearings, the TDO unit of 4T-423184UTG integrates both rows in one article: the 280 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Double-row capacity is not twice a single-row bearing: the printed 6150 kN C already accounts for load sharing between the two rows of 4T-423184UTG, so apply it directly in the L10 calculation. TDO construction means the two cone assemblies of 4T-423184UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 420 mm shaft. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-423184UTG; the double cup must seat square across its full 280 mm width.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 420 mm bore the 4T-423184UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 6150 kN C level.",
      "The 430 light plan keeps 4T-423184UTG narrower and faster than the 432 heavy execution of the same 420 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-423184UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 6150 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 700 mm OD clamping uniformly around the circumference.",
      "The 6150/9700 kN ratings and 705 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423184UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423184UTG?",
        "a": "4T-423184UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 420 mm bore, 700 mm outside diameter and 280 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 6150 kN, C0 9700 kN, Cu 705 kN, grease limiting speed 360 r/min, oil speed 510 r/min, mass about 380 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 420 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423184UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423184UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 280 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423184UTG mean?",
        "a": "Suffix reading on 423184UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423184UTG list two speeds, 360 and 510 r/min?",
        "a": "The lower figure, 360 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423184UTG at 510 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423184UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423184utg",
      "4t-423184utg",
      "＊423184utg",
      "423184UTG",
      "4T-423184UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323088UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323088UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 440,
    "D_mm": 650,
    "B_mm": 157,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3350,
    "static_load_kN": 5450,
    "fatigue_load_limit_kN": 400,
    "limiting_speed_rpm": 370,
    "max_rpm": 370,
    "speed_oil_rpm": 520,
    "weight_g": 180000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-323088UTG denotes the heavy-duty 432-family TDO double-row series — a 440 mm bore double-row tapered unit rated 3350 kN basic dynamic and 5450 kN static. Unlike a pair of single-row bearings, the TDO unit of 4T-323088UTG integrates both rows in one article: the 157 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Grease relubrication at the 370 r/min limiting speed must reach both roller rows; sustaining 520 r/min needs an oil supply with defined flow through the double cup. Because the unit is preset, mounting 4T-323088UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-323088UTG; the double cup must seat square across its full 157 mm width.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 440 mm bore the 4T-323088UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3350 kN C level.",
      "The 432 heavy plan gives 4T-323088UTG its 157 mm width and 3350 kN rating at the 440 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 400 kN Cu.",
      "Open 4T-323088UTG units have no seals: the housing must seal both rows or the 370 r/min grease figure is meaningless once contamination enters.",
      "The internal clearance of 4T-323088UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 157 mm width, load spread and clearance logic of 4T-323088UTG are unit-specific.",
      "The 3350/5450 kN ratings and 400 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323088UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323088UTG?",
        "a": "4T-323088UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 440 mm bore, 650 mm outside diameter and 157 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3350 kN, C0 5450 kN, Cu 400 kN, grease limiting speed 370 r/min, oil speed 520 r/min, mass about 180 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 440 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323088UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323088UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 157 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323088UTG mean?",
        "a": "Suffix reading on 323088UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323088UTG list two speeds, 370 and 520 r/min?",
        "a": "The lower figure, 370 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323088UTG at 520 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323088UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323088utg",
      "4t-323088utg",
      "＊323088utg",
      "323088UTG",
      "4T-323088UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413088UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413088UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 440,
    "D_mm": 650,
    "B_mm": 157,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3150,
    "static_load_kN": 5150,
    "fatigue_load_limit_kN": 375,
    "limiting_speed_rpm": 370,
    "max_rpm": 370,
    "speed_oil_rpm": 520,
    "weight_g": 160000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-413088UTG denotes the light-duty 430-family TDO double-row series — a 440 mm bore double-row tapered unit rated 3150 kN basic dynamic and 5150 kN static. Reading the designation: the last two digits 88 are the bore code, ×5 = 440 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. Selection: C 3150 kN against C0 5150 kN gives a C0/C ratio of 1.63; the two rows of 4T-413088UTG share the combined load as one bearing position. The internal clearance of 4T-413088UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 157 mm overall width is the finished dimension. With a rotating shaft a m6/n6 seat on the 440 mm journal and a located cup in the housing are typical practice for 4T-413088UTG.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 440 mm bore the 4T-413088UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3150 kN C level.",
      "The 430 light plan keeps 4T-413088UTG narrower and faster than the 432 heavy execution of the same 440 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Order by the full 413088UTG code including suffixes — U, X, DX, E1 and UTG variants share the 440 mm bore but are different articles with different internal geometry.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 157 mm width, load spread and clearance logic of 4T-413088UTG are unit-specific.",
      "At inspection do not mix the cone assemblies of 4T-413088UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 3150/5150 kN ratings and 375 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413088UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413088UTG?",
        "a": "4T-413088UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 440 mm bore, 650 mm outside diameter and 157 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3150 kN, C0 5150 kN, Cu 375 kN, grease limiting speed 370 r/min, oil speed 520 r/min, mass about 160 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 440 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413088UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413088UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 157 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413088UTG mean?",
        "a": "Suffix reading on 413088UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413088UTG list two speeds, 370 and 520 r/min?",
        "a": "The lower figure, 370 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413088UTG at 520 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413088UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413088utg",
      "4t-413088utg",
      "＊413088utg",
      "413088UTG",
      "4T-413088UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423088UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423088UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 440,
    "D_mm": 650,
    "B_mm": 196,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3350,
    "static_load_kN": 5450,
    "fatigue_load_limit_kN": 400,
    "limiting_speed_rpm": 370,
    "max_rpm": 370,
    "speed_oil_rpm": 520,
    "weight_g": 190000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423088UTG is the NTN 4T catalogue entry for a 440×650×196 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Suffix reading on 423088UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Grease relubrication at the 370 r/min limiting speed must reach both roller rows; sustaining 520 r/min needs an oil supply with defined flow through the double cup. TDO construction means the two cone assemblies of 4T-423088UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 440 mm shaft. Axial clamping of the double cup must be uniform around the 650 mm OD; a cocked end cover pinches one row and destroys the factory clearance setting.",
    "applications": [
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 440 mm bore the 4T-423088UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3350 kN C level.",
      "The 430 light plan keeps 4T-423088UTG narrower and faster than the 432 heavy execution of the same 440 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 196 mm width, load spread and clearance logic of 4T-423088UTG are unit-specific.",
      "Order by the full 423088UTG code including suffixes — U, X, DX, E1 and UTG variants share the 440 mm bore but are different articles with different internal geometry.",
      "The 105.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-423088UTG or the cones bottom out on the radius.",
      "The 3350/5450 kN ratings and 400 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423088UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423088UTG?",
        "a": "4T-423088UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 440 mm bore, 650 mm outside diameter and 196 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3350 kN, C0 5450 kN, Cu 400 kN, grease limiting speed 370 r/min, oil speed 520 r/min, mass about 190 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 440 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423088UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423088UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 196 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423088UTG mean?",
        "a": "Suffix reading on 423088UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423088UTG list two speeds, 370 and 520 r/min?",
        "a": "The lower figure, 370 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423088UTG at 520 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423088UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423088utg",
      "4t-423088utg",
      "＊423088utg",
      "423088UTG",
      "4T-423088UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323188UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323188UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 440,
    "D_mm": 720,
    "B_mm": 226,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 6400,
    "static_load_kN": 10300,
    "fatigue_load_limit_kN": 740,
    "limiting_speed_rpm": 340,
    "max_rpm": 340,
    "speed_oil_rpm": 480,
    "weight_g": 360000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-323188UTG denotes the heavy-duty 432-family TDO double-row series — a 440 mm bore double-row tapered unit rated 6400 kN basic dynamic and 10300 kN static. Suffix reading on 323188UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Grease relubrication at the 340 r/min limiting speed must reach both roller rows; sustaining 480 r/min needs an oil supply with defined flow through the double cup. TDO construction means the two cone assemblies of 4T-323188UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 440 mm shaft. Induction heating to max 120 °C is the standard fitting method at this 440 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 440 mm bore the 4T-323188UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 6400 kN C level.",
      "The 432 heavy plan gives 4T-323188UTG its 226 mm width and 6400 kN rating at the 440 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 740 kN Cu.",
      "An unloaded 4T-323188UTG near 340 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 6400 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The internal clearance of 4T-323188UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 6400/10300 kN ratings and 740 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323188UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323188UTG?",
        "a": "4T-323188UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 440 mm bore, 720 mm outside diameter and 226 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 6400 kN, C0 10300 kN, Cu 740 kN, grease limiting speed 340 r/min, oil speed 480 r/min, mass about 360 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 440 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323188UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323188UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 226 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323188UTG mean?",
        "a": "Suffix reading on 323188UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323188UTG list two speeds, 340 and 480 r/min?",
        "a": "The lower figure, 340 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323188UTG at 480 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323188UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323188utg",
      "4t-323188utg",
      "＊323188utg",
      "323188UTG",
      "4T-323188UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413188UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413188UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 440,
    "D_mm": 720,
    "B_mm": 226,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 5150,
    "static_load_kN": 7800,
    "fatigue_load_limit_kN": 560,
    "limiting_speed_rpm": 340,
    "max_rpm": 340,
    "speed_oil_rpm": 480,
    "weight_g": 330000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-413188UTG denotes the light-duty 430-family TDO double-row series — a 440 mm bore double-row tapered unit rated 5150 kN basic dynamic and 7800 kN static. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 440 mm bore the 432 execution carries a wider, heavier section than the 430. Grease relubrication at the 340 r/min limiting speed must reach both roller rows; sustaining 480 r/min needs an oil supply with defined flow through the double cup. Because the unit is preset, mounting 4T-413188UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Mount 4T-413188UTG as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 440 mm bore the 4T-413188UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 5150 kN C level.",
      "The 430 light plan keeps 4T-413188UTG narrower and faster than the 432 heavy execution of the same 440 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 226 mm width, load spread and clearance logic of 4T-413188UTG are unit-specific.",
      "At inspection do not mix the cone assemblies of 4T-413188UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 5150 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "The 5150/7800 kN ratings and 560 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413188UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413188UTG?",
        "a": "4T-413188UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 440 mm bore, 720 mm outside diameter and 226 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 5150 kN, C0 7800 kN, Cu 560 kN, grease limiting speed 340 r/min, oil speed 480 r/min, mass about 330 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 440 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413188UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413188UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 226 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413188UTG mean?",
        "a": "Suffix reading on 413188UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413188UTG list two speeds, 340 and 480 r/min?",
        "a": "The lower figure, 340 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413188UTG at 480 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413188UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413188utg",
      "4t-413188utg",
      "＊413188utg",
      "413188UTG",
      "4T-413188UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423188UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423188UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 440,
    "D_mm": 720,
    "B_mm": 283,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 6400,
    "static_load_kN": 10300,
    "fatigue_load_limit_kN": 740,
    "limiting_speed_rpm": 340,
    "max_rpm": 340,
    "speed_oil_rpm": 480,
    "weight_g": 460000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423188UTG is the NTN 4T catalogue entry for a 440×720×283 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 423188UTG reads accordingly. Grease relubrication at the 340 r/min limiting speed must reach both roller rows; sustaining 480 r/min needs an oil supply with defined flow through the double cup. The internal clearance of 4T-423188UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 283 mm overall width is the finished dimension. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-423188UTG are ground as a unit.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 440 mm bore the 4T-423188UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 6400 kN C level.",
      "The 430 light plan keeps 4T-423188UTG narrower and faster than the 432 heavy execution of the same 440 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 140.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-423188UTG or the cones bottom out on the radius.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 720 mm OD clamping uniformly around the circumference.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 720 mm OD clamping uniformly around the circumference.",
      "The 6400/10300 kN ratings and 740 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423188UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423188UTG?",
        "a": "4T-423188UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 440 mm bore, 720 mm outside diameter and 283 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 6400 kN, C0 10300 kN, Cu 740 kN, grease limiting speed 340 r/min, oil speed 480 r/min, mass about 460 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 440 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423188UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423188UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 283 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423188UTG mean?",
        "a": "Suffix reading on 423188UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423188UTG list two speeds, 340 and 480 r/min?",
        "a": "The lower figure, 340 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423188UTG at 480 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423188UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423188utg",
      "4t-423188utg",
      "＊423188utg",
      "423188UTG",
      "4T-423188UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323092UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323092UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 460,
    "D_mm": 680,
    "B_mm": 163,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3950,
    "static_load_kN": 6750,
    "fatigue_load_limit_kN": 485,
    "limiting_speed_rpm": 350,
    "max_rpm": 350,
    "speed_oil_rpm": 500,
    "weight_g": 200000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323092UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 460×680×163 mm. Suffix reading on 323092UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Speed planning uses both catalogue columns: grease 350 r/min is the mechanical ceiling, oil 500 r/min with oil lubrication — a 150 r/min margin at this size. The internal clearance of 4T-323092UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 163 mm overall width is the finished dimension. Mount 4T-323092UTG as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 460 mm bore the 4T-323092UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3950 kN C level.",
      "The 432 heavy plan gives 4T-323092UTG its 163 mm width and 3950 kN rating at the 460 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 485 kN Cu.",
      "At inspection do not mix the cone assemblies of 4T-323092UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Order by the full 323092UTG code including suffixes — U, X, DX, E1 and UTG variants share the 460 mm bore but are different articles with different internal geometry.",
      "An unloaded 4T-323092UTG near 350 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 3950/6750 kN ratings and 485 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323092UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323092UTG?",
        "a": "4T-323092UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 460 mm bore, 680 mm outside diameter and 163 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3950 kN, C0 6750 kN, Cu 485 kN, grease limiting speed 350 r/min, oil speed 500 r/min, mass about 200 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 460 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323092UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323092UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 163 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323092UTG mean?",
        "a": "Suffix reading on 323092UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323092UTG list two speeds, 350 and 500 r/min?",
        "a": "The lower figure, 350 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323092UTG at 500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323092UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323092utg",
      "4t-323092utg",
      "＊323092utg",
      "323092UTG",
      "4T-323092UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413092UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413092UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 460,
    "D_mm": 680,
    "B_mm": 163,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3350,
    "static_load_kN": 5350,
    "fatigue_load_limit_kN": 390,
    "limiting_speed_rpm": 350,
    "max_rpm": 350,
    "speed_oil_rpm": 500,
    "weight_g": 180000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413092UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 460×680×163 mm. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 460 mm bore the 432 execution carries a wider, heavier section than the 430. The 110.0 mm radial section over the 460 mm bore carries two roller rows across the 163 mm width; abutment shoulders must clear both cone bores and the double-cup OD. Because the unit is preset, mounting 4T-413092UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-413092UTG; the double cup must seat square across its full 163 mm width.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 460 mm bore the 4T-413092UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3350 kN C level.",
      "The 430 light plan keeps 4T-413092UTG narrower and faster than the 432 heavy execution of the same 460 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The internal clearance of 4T-413092UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 163 mm width, load spread and clearance logic of 4T-413092UTG are unit-specific.",
      "The 110.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-413092UTG or the cones bottom out on the radius.",
      "The 3350/5350 kN ratings and 390 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413092UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413092UTG?",
        "a": "4T-413092UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 460 mm bore, 680 mm outside diameter and 163 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3350 kN, C0 5350 kN, Cu 390 kN, grease limiting speed 350 r/min, oil speed 500 r/min, mass about 180 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 460 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413092UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413092UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 163 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413092UTG mean?",
        "a": "Suffix reading on 413092UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413092UTG list two speeds, 350 and 500 r/min?",
        "a": "The lower figure, 350 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413092UTG at 500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413092UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413092utg",
      "4t-413092utg",
      "＊413092utg",
      "413092UTG",
      "4T-413092UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423092UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423092UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 460,
    "D_mm": 680,
    "B_mm": 204,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3950,
    "static_load_kN": 6750,
    "fatigue_load_limit_kN": 485,
    "limiting_speed_rpm": 350,
    "max_rpm": 350,
    "speed_oil_rpm": 500,
    "weight_g": 230000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "NTN supplies this 460 mm shaft position as 4T-423092UTG: a factory-adjusted double-row tapered roller bearing whose two roller rows share one double cup, overall width 204 mm. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 423092UTG reads accordingly. Speed planning uses both catalogue columns: grease 350 r/min is the mechanical ceiling, oil 500 r/min with oil lubrication — a 150 r/min margin at this size. Because the unit is preset, mounting 4T-423092UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. At 3950 kN C the unit offers about 8.6 kN per millimetre of the 460 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 500 r/min.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 460 mm bore the 4T-423092UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3950 kN C level.",
      "The 430 light plan keeps 4T-423092UTG narrower and faster than the 432 heavy execution of the same 460 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 680 mm OD clamping uniformly around the circumference.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 204 mm width, load spread and clearance logic of 4T-423092UTG are unit-specific.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-423092UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 3950/6750 kN ratings and 485 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423092UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423092UTG?",
        "a": "4T-423092UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 460 mm bore, 680 mm outside diameter and 204 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3950 kN, C0 6750 kN, Cu 485 kN, grease limiting speed 350 r/min, oil speed 500 r/min, mass about 230 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 460 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423092UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423092UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 204 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423092UTG mean?",
        "a": "Suffix reading on 423092UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423092UTG list two speeds, 350 and 500 r/min?",
        "a": "The lower figure, 350 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423092UTG at 500 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423092UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423092utg",
      "4t-423092utg",
      "＊423092utg",
      "423092UTG",
      "4T-423092UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323192UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323192UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 460,
    "D_mm": 760,
    "B_mm": 240,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 6300,
    "static_load_kN": 10300,
    "fatigue_load_limit_kN": 725,
    "limiting_speed_rpm": 320,
    "max_rpm": 320,
    "speed_oil_rpm": 450,
    "weight_g": 430000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323192UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 460×760×240 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-323192UTG integrates both rows in one article: the 240 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The fatigue load limit Cu printed for 4T-323192UTG is 725 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. The internal clearance of 4T-323192UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 240 mm overall width is the finished dimension. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-323192UTG.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 460 mm bore the 4T-323192UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 6300 kN C level.",
      "The 432 heavy plan gives 4T-323192UTG its 240 mm width and 6300 kN rating at the 460 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 725 kN Cu.",
      "The 150.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-323192UTG or the cones bottom out on the radius.",
      "The 6300 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.",
      "Order by the full 323192UTG code including suffixes — U, X, DX, E1 and UTG variants share the 460 mm bore but are different articles with different internal geometry.",
      "The 6300/10300 kN ratings and 725 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323192UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323192UTG?",
        "a": "4T-323192UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 460 mm bore, 760 mm outside diameter and 240 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 6300 kN, C0 10300 kN, Cu 725 kN, grease limiting speed 320 r/min, oil speed 450 r/min, mass about 430 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 460 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323192UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323192UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 240 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323192UTG mean?",
        "a": "Suffix reading on 323192UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323192UTG list two speeds, 320 and 450 r/min?",
        "a": "The lower figure, 320 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323192UTG at 450 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323192UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323192utg",
      "4t-323192utg",
      "＊323192utg",
      "323192UTG",
      "4T-323192UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423192UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423192UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 460,
    "D_mm": 760,
    "B_mm": 300,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 6300,
    "static_load_kN": 10300,
    "fatigue_load_limit_kN": 725,
    "limiting_speed_rpm": 320,
    "max_rpm": 320,
    "speed_oil_rpm": 450,
    "weight_g": 480000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423192UTG is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 460×760×300 mm. Suffix reading on 423192UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. The fatigue load limit Cu printed for 4T-423192UTG is 725 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. The internal clearance of 4T-423192UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 300 mm overall width is the finished dimension. Induction heating to max 120 °C is the standard fitting method at this 460 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 460 mm bore the 4T-423192UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 6300 kN C level.",
      "The 430 light plan keeps 4T-423192UTG narrower and faster than the 432 heavy execution of the same 460 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "At inspection do not mix the cone assemblies of 4T-423192UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 760 mm OD clamping uniformly around the circumference.",
      "Open 4T-423192UTG units have no seals: the housing must seal both rows or the 320 r/min grease figure is meaningless once contamination enters.",
      "The 6300/10300 kN ratings and 725 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423192UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423192UTG?",
        "a": "4T-423192UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 460 mm bore, 760 mm outside diameter and 300 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 6300 kN, C0 10300 kN, Cu 725 kN, grease limiting speed 320 r/min, oil speed 450 r/min, mass about 480 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 460 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423192UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423192UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 300 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423192UTG mean?",
        "a": "Suffix reading on 423192UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423192UTG list two speeds, 320 and 450 r/min?",
        "a": "The lower figure, 320 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423192UTG at 450 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423192UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423192utg",
      "4t-423192utg",
      "＊423192utg",
      "423192UTG",
      "4T-423192UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323096UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323096UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 480,
    "D_mm": 700,
    "B_mm": 165,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3900,
    "static_load_kN": 6700,
    "fatigue_load_limit_kN": 480,
    "limiting_speed_rpm": 330,
    "max_rpm": 330,
    "speed_oil_rpm": 470,
    "weight_g": 210000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323096UTG belongs to the heavy-duty 432-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 480 mm bore the 432 execution carries a wider, heavier section than the 430. The 110.0 mm radial section over the 480 mm bore carries two roller rows across the 165 mm width; abutment shoulders must clear both cone bores and the double-cup OD. Because the unit is preset, mounting 4T-323096UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Moment loads are reacted by the wide row spread of the TDO unit; if the shaft also carries a floating bearing, keep the float clear of 4T-323096UTG's locating position.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 480 mm bore the 4T-323096UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3900 kN C level.",
      "The 432 heavy plan gives 4T-323096UTG its 165 mm width and 3900 kN rating at the 480 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 480 kN Cu.",
      "The internal clearance of 4T-323096UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 165 mm width, load spread and clearance logic of 4T-323096UTG are unit-specific.",
      "An unloaded 4T-323096UTG near 330 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 3900/6700 kN ratings and 480 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323096UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323096UTG?",
        "a": "4T-323096UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 480 mm bore, 700 mm outside diameter and 165 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3900 kN, C0 6700 kN, Cu 480 kN, grease limiting speed 330 r/min, oil speed 470 r/min, mass about 210 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 480 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323096UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323096UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 165 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323096UTG mean?",
        "a": "Suffix reading on 323096UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323096UTG list two speeds, 330 and 470 r/min?",
        "a": "The lower figure, 330 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323096UTG at 470 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323096UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323096utg",
      "4t-323096utg",
      "＊323096utg",
      "323096UTG",
      "4T-323096UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "413096UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-413096UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 480,
    "D_mm": 700,
    "B_mm": 165,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3200,
    "static_load_kN": 5000,
    "fatigue_load_limit_kN": 360,
    "limiting_speed_rpm": 330,
    "max_rpm": 330,
    "speed_oil_rpm": 470,
    "weight_g": 190000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-413096UTG belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Unlike a pair of single-row bearings, the TDO unit of 4T-413096UTG integrates both rows in one article: the 165 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The 110.0 mm radial section over the 480 mm bore carries two roller rows across the 165 mm width; abutment shoulders must clear both cone bores and the double-cup OD. The internal clearance of 4T-413096UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 165 mm overall width is the finished dimension. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-413096UTG; the double cup must seat square across its full 165 mm width.",
    "applications": [
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 480 mm bore the 4T-413096UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3200 kN C level.",
      "The 430 light plan keeps 4T-413096UTG narrower and faster than the 432 heavy execution of the same 480 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-413096UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-413096UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Open 4T-413096UTG units have no seals: the housing must seal both rows or the 330 r/min grease figure is meaningless once contamination enters.",
      "The 3200/5000 kN ratings and 360 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-413096UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-413096UTG?",
        "a": "4T-413096UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 480 mm bore, 700 mm outside diameter and 165 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3200 kN, C0 5000 kN, Cu 360 kN, grease limiting speed 330 r/min, oil speed 470 r/min, mass about 190 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 480 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-413096UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-413096UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 165 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 413096UTG mean?",
        "a": "Suffix reading on 413096UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-413096UTG list two speeds, 330 and 470 r/min?",
        "a": "The lower figure, 330 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-413096UTG at 470 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "413096UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "413096utg",
      "4t-413096utg",
      "＊413096utg",
      "413096UTG",
      "4T-413096UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423096UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423096UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 480,
    "D_mm": 700,
    "B_mm": 206,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3900,
    "static_load_kN": 6700,
    "fatigue_load_limit_kN": 480,
    "limiting_speed_rpm": 330,
    "max_rpm": 330,
    "speed_oil_rpm": 470,
    "weight_g": 240000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-423096UTG denotes the light-duty 430-family TDO double-row series — a 480 mm bore double-row tapered unit rated 3900 kN basic dynamic and 6700 kN static. Reading the designation: the last two digits 96 are the bore code, ×5 = 480 mm (codes 00–03 use the 10/12/15/17 exception table); the leading digits place the bearing in the light-duty 430-family TDO double-row series. The 110.0 mm radial section over the 480 mm bore carries two roller rows across the 206 mm width; abutment shoulders must clear both cone bores and the double-cup OD. TDO construction means the two cone assemblies of 4T-423096UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 480 mm shaft. Mount 4T-423096UTG as one article: lift on the double cup, never on a single cone, or the preset alignment of the two rows is disturbed.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 480 mm bore the 4T-423096UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3900 kN C level.",
      "The 430 light plan keeps 4T-423096UTG narrower and faster than the 432 heavy execution of the same 480 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Grease packs must leave free volume across the 206 mm width; over-greasing a unit churning near the 470 r/min oil-band speed raises temperature and expels the grease.",
      "Open 4T-423096UTG units have no seals: the housing must seal both rows or the 330 r/min grease figure is meaningless once contamination enters.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-423096UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 3900/6700 kN ratings and 480 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423096UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423096UTG?",
        "a": "4T-423096UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 480 mm bore, 700 mm outside diameter and 206 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3900 kN, C0 6700 kN, Cu 480 kN, grease limiting speed 330 r/min, oil speed 470 r/min, mass about 240 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 480 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423096UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423096UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 206 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423096UTG mean?",
        "a": "Suffix reading on 423096UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423096UTG list two speeds, 330 and 470 r/min?",
        "a": "The lower figure, 330 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423096UTG at 470 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423096UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423096utg",
      "4t-423096utg",
      "＊423096utg",
      "423096UTG",
      "4T-423096UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "323196UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-323196UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 480,
    "D_mm": 790,
    "B_mm": 248,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 6750,
    "static_load_kN": 11100,
    "fatigue_load_limit_kN": 775,
    "limiting_speed_rpm": 300,
    "max_rpm": 300,
    "speed_oil_rpm": 430,
    "weight_g": 480000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-323196UTG belongs to the heavy-duty 432-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 323196UTG reads accordingly. The fatigue load limit Cu printed for 4T-323196UTG is 775 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-323196UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 480 mm shaft. Re-lubrication holes and grooves of the housing should line up with the cup's mid-width so fresh grease reaches both roller rows of 4T-323196UTG.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 480 mm bore the 4T-323196UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 6750 kN C level.",
      "The 432 heavy plan gives 4T-323196UTG its 248 mm width and 6750 kN rating at the 480 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 775 kN Cu.",
      "Order by the full 323196UTG code including suffixes — U, X, DX, E1 and UTG variants share the 480 mm bore but are different articles with different internal geometry.",
      "At inspection do not mix the cone assemblies of 4T-323196UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "At inspection do not mix the cone assemblies of 4T-323196UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "The 6750/11100 kN ratings and 775 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323196UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-323196UTG?",
        "a": "4T-323196UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 480 mm bore, 790 mm outside diameter and 248 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 6750 kN, C0 11100 kN, Cu 775 kN, grease limiting speed 300 r/min, oil speed 430 r/min, mass about 480 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 480 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-323196UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-323196UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 248 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 323196UTG mean?",
        "a": "Suffix reading on 323196UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-323196UTG list two speeds, 300 and 430 r/min?",
        "a": "The lower figure, 300 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323196UTG at 430 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "323196UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "323196utg",
      "4t-323196utg",
      "＊323196utg",
      "323196UTG",
      "4T-323196UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "423196UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-423196UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 480,
    "D_mm": 790,
    "B_mm": 310,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 6750,
    "static_load_kN": 11100,
    "fatigue_load_limit_kN": 775,
    "limiting_speed_rpm": 310,
    "max_rpm": 310,
    "speed_oil_rpm": 430,
    "weight_g": 540000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-423196UTG belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 480 mm bore the 432 execution carries a wider, heavier section than the 430. The fatigue load limit Cu printed for 4T-423196UTG is 775 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. TDO construction means the two cone assemblies of 4T-423196UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 480 mm shaft. Induction heating to max 120 °C is the standard fitting method at this 480 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 480 mm bore the 4T-423196UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 6750 kN C level.",
      "The 430 light plan keeps 4T-423196UTG narrower and faster than the 432 heavy execution of the same 480 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The internal clearance of 4T-423196UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "The 155.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-423196UTG or the cones bottom out on the radius.",
      "An unloaded 4T-423196UTG near 310 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The 6750/11100 kN ratings and 775 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-423196UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-423196UTG?",
        "a": "4T-423196UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 480 mm bore, 790 mm outside diameter and 310 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 6750 kN, C0 11100 kN, Cu 775 kN, grease limiting speed 310 r/min, oil speed 430 r/min, mass about 540 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 480 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-423196UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-423196UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 310 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 423196UTG mean?",
        "a": "Suffix reading on 423196UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-423196UTG list two speeds, 310 and 430 r/min?",
        "a": "The lower figure, 310 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-423196UTG at 430 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "423196UTG",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "423196utg",
      "4t-423196utg",
      "＊423196utg",
      "423196UTG",
      "4T-423196UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "3230-500UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-3230/500UTG",
    "series": "4t-432-series",
    "type": "tapered_roller",
    "d_mm": 500,
    "D_mm": 720,
    "B_mm": 167,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3950,
    "static_load_kN": 6900,
    "fatigue_load_limit_kN": 485,
    "limiting_speed_rpm": 320,
    "max_rpm": 320,
    "speed_oil_rpm": 450,
    "weight_g": 220000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-3230/500UTG is the NTN 4T catalogue entry for a 500×720×167 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. Large sizes continue the plans under different leading digits: 4130/4131 and 4230/4231 belong to the 430-family dimension plan, while 3230/3231 continue the 432 heavy plan — 3230/500UTG reads accordingly. The 7.9 kN of dynamic capacity per millimetre of bore summarises the 3950 kN rating over the 500 mm bore — compare substitution candidates on this ratio and on the 167 mm width. TDO construction means the two cone assemblies of 4T-3230/500UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 500 mm shaft. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-3230/500UTG; the double cup must seat square across its full 167 mm width.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "false brinelling on a stored or standby unit exposed to vibration"
    ],
    "pitfalls": [
      "At 500 mm bore the 4T-3230/500UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3950 kN C level.",
      "The 432 heavy plan gives 4T-3230/500UTG its 167 mm width and 3950 kN rating at the 500 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 485 kN Cu.",
      "Grease packs must leave free volume across the 167 mm width; over-greasing a unit churning near the 450 r/min oil-band speed raises temperature and expels the grease.",
      "At inspection do not mix the cone assemblies of 4T-3230/500UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Order by the full 3230/500UTG code including suffixes — U, X, DX, E1 and UTG variants share the 500 mm bore but are different articles with different internal geometry.",
      "The 3950/6900 kN ratings and 485 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-3230/500UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-3230/500UTG?",
        "a": "4T-3230/500UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 500 mm bore, 720 mm outside diameter and 167 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3950 kN, C0 6900 kN, Cu 485 kN, grease limiting speed 320 r/min, oil speed 450 r/min, mass about 220 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 500 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-3230/500UTG belongs to the heavy-duty 432-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-3230/500UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 167 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 3230/500UTG mean?",
        "a": "Suffix reading on 3230/500UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-3230/500UTG list two speeds, 320 and 450 r/min?",
        "a": "The lower figure, 320 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-3230/500UTG at 450 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "3230",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=202",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "3230-500utg",
      "4t-3230-500utg",
      "＊3230-500utg",
      "3230-500UTG",
      "4T-3230-500UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "4130-500UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-4130/500UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 500,
    "D_mm": 720,
    "B_mm": 167,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3350,
    "static_load_kN": 5400,
    "fatigue_load_limit_kN": 380,
    "limiting_speed_rpm": 320,
    "max_rpm": 320,
    "speed_oil_rpm": 450,
    "weight_g": 200000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-4130/500UTG at 500 mm bore, 720 mm OD and 167 mm overall width, with a grease limiting speed of 320 r/min and an oil ceiling of 450 r/min. Reading the designation: the figure after the slash prints the 500 mm bore directly in NTN's slash-size convention for large double-row bearings; the leading digits place the bearing in the light-duty 430-family TDO double-row series. The fatigue load limit Cu printed for 4T-4130/500UTG is 380 kN — the equivalent-load floor below which high reliability is expected even under contamination in the adjusted-life equation. Because the unit is preset, mounting 4T-4130/500UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-4130/500UTG; the double cup must seat square across its full 167 mm width.",
    "applications": [
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "thermal distress when the oil supply sized for one row starves the second row"
    ],
    "pitfalls": [
      "At 500 mm bore the 4T-4130/500UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3350 kN C level.",
      "The 430 light plan keeps 4T-4130/500UTG narrower and faster than the 432 heavy execution of the same 500 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "The 110.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-4130/500UTG or the cones bottom out on the radius.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 167 mm width, load spread and clearance logic of 4T-4130/500UTG are unit-specific.",
      "The 110.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-4130/500UTG or the cones bottom out on the radius.",
      "The 3350/5400 kN ratings and 380 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-4130/500UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-4130/500UTG?",
        "a": "4T-4130/500UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 500 mm bore, 720 mm outside diameter and 167 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3350 kN, C0 5400 kN, Cu 380 kN, grease limiting speed 320 r/min, oil speed 450 r/min, mass about 200 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 500 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-4130/500UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-4130/500UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 167 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 4130/500UTG mean?",
        "a": "Suffix reading on 4130/500UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-4130/500UTG list two speeds, 320 and 450 r/min?",
        "a": "The lower figure, 320 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-4130/500UTG at 450 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "4130",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4130-500utg",
      "4t-4130-500utg",
      "＊4130-500utg",
      "4130-500UTG",
      "4T-4130-500UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "4230-500UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-4230/500UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 500,
    "D_mm": 720,
    "B_mm": 209,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3950,
    "static_load_kN": 6900,
    "fatigue_load_limit_kN": 485,
    "limiting_speed_rpm": 320,
    "max_rpm": 320,
    "speed_oil_rpm": 450,
    "weight_g": 250000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-4230/500UTG is the NTN 4T catalogue entry for a 500×720×209 mm double-row tapered roller bearing — the TDO arrangement reacts radial load plus thrust in both directions without a second bearing. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 500 mm bore the 432 execution carries a wider, heavier section than the 430. Grease relubrication at the 320 r/min limiting speed must reach both roller rows; sustaining 450 r/min needs an oil supply with defined flow through the double cup. The internal clearance of 4T-4230/500UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 209 mm overall width is the finished dimension. With a rotating shaft a m6/n6 seat on the 500 mm journal and a located cup in the housing are typical practice for 4T-4230/500UTG.",
    "applications": [
      "heavy press and forging-machine drives",
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "fretting corrosion on a loose cone seat that creeps under rotating load"
    ],
    "pitfalls": [
      "At 500 mm bore the 4T-4230/500UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3950 kN C level.",
      "The 430 light plan keeps 4T-4230/500UTG narrower and faster than the 432 heavy execution of the same 500 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-4230/500UTG near 320 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "The internal clearance of 4T-4230/500UTG is factory-set: no end-play adjustment exists at mounting, and any attempt to set preload with a shaft nut overloads one row.",
      "Order by the full 4230/500UTG code including suffixes — U, X, DX, E1 and UTG variants share the 500 mm bore but are different articles with different internal geometry.",
      "The 3950/6900 kN ratings and 485 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-4230/500UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-4230/500UTG?",
        "a": "4T-4230/500UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 500 mm bore, 720 mm outside diameter and 209 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3950 kN, C0 6900 kN, Cu 485 kN, grease limiting speed 320 r/min, oil speed 450 r/min, mass about 250 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 500 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-4230/500UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-4230/500UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 209 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 4230/500UTG mean?",
        "a": "Suffix reading on 4230/500UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-4230/500UTG list two speeds, 320 and 450 r/min?",
        "a": "The lower figure, 320 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-4230/500UTG at 450 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "4230",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4230-500utg",
      "4t-4230-500utg",
      "＊4230-500utg",
      "4230-500UTG",
      "4T-4230-500UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "4131-500UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-4131/500UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 500,
    "D_mm": 830,
    "B_mm": 264,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 6700,
    "static_load_kN": 10500,
    "fatigue_load_limit_kN": 725,
    "limiting_speed_rpm": 290,
    "max_rpm": 290,
    "speed_oil_rpm": 410,
    "weight_g": 530000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "4T-4131/500UTG belongs to the light-duty 430-family TDO double-row series of NTN double-row tapered roller bearings; the unit is mounted as one article and its internal clearance is set at the factory, not on the shaft. Suffix reading on 4131/500UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles. Grease relubrication at the 290 r/min limiting speed must reach both roller rows; sustaining 410 r/min needs an oil supply with defined flow through the double cup. Because the unit is preset, mounting 4T-4131/500UTG resembles mounting a double-row spherical or cylindrical bearing: seat the unit, clamp axially to the stated end cover torque, and verify rotation — no end-play measurement is required. At 6700 kN C the unit offers about 13.4 kN per millimetre of the 500 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 410 r/min.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage damage when the unit is lifted by one cone instead of the double cup during fitting",
      "rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load"
    ],
    "pitfalls": [
      "At 500 mm bore the 4T-4131/500UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 6700 kN C level.",
      "The 430 light plan keeps 4T-4131/500UTG narrower and faster than the 432 heavy execution of the same 500 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-4131/500UTG near 290 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "Never interchange a TDO double-row unit with two single-row bearings of similar size: the 264 mm width, load spread and clearance logic of 4T-4131/500UTG are unit-specific.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-4131/500UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "The 6700/10500 kN ratings and 725 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-4131/500UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-4131/500UTG?",
        "a": "4T-4131/500UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 500 mm bore, 830 mm outside diameter and 264 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 6700 kN, C0 10500 kN, Cu 725 kN, grease limiting speed 290 r/min, oil speed 410 r/min, mass about 530 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 500 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-4131/500UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-4131/500UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 264 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 4131/500UTG mean?",
        "a": "Suffix reading on 4131/500UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-4131/500UTG list two speeds, 290 and 410 r/min?",
        "a": "The lower figure, 290 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-4131/500UTG at 410 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "4131",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=199",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4131-500utg",
      "4t-4131-500utg",
      "＊4131-500utg",
      "4131-500UTG",
      "4T-4131-500UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "4130-530UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-4130/530UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 530,
    "D_mm": 780,
    "B_mm": 185,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 3750,
    "static_load_kN": 5900,
    "fatigue_load_limit_kN": 410,
    "limiting_speed_rpm": 290,
    "max_rpm": 290,
    "speed_oil_rpm": 420,
    "weight_g": 270000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "For a 530 mm shaft needing a compact two-direction thrust location, NTN lists 4T-4130/530UTG, a TDO double-row 4T unit of 3750 kN C and 5900 kN C0 in the light-duty 430-family TDO double-row series. Unlike a pair of single-row bearings, the TDO unit of 4T-4130/530UTG integrates both rows in one article: the 185 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. Grease relubrication at the 290 r/min limiting speed must reach both roller rows; sustaining 420 r/min needs an oil supply with defined flow through the double cup. The internal clearance of 4T-4130/530UTG is set at the factory by the double cup and spacer-less grinding; do not attempt to re-adjust it with shaft nuts — the 185 mm overall width is the finished dimension. Fillet radii and shoulder heights must follow the 2203E mounting table for 4T-4130/530UTG; the double cup must seat square across its full 185 mm width.",
    "applications": [
      "large shredder and recycler main shafts",
      "power-plant mill and fan shafts",
      "rolling-mill roll-neck and pinion-stand positions",
      "mine hoist and dragline drum shafts"
    ],
    "failure_modes": [
      "edge loading on one row when the housing seats the double cup cocked across its width",
      "overheated running after a field attempt to \"tighten up\" the factory-set internal clearance",
      "one-row flaking when a bent shaft concentrates the combined load on a single row of the pair",
      "cage fatigue after continuous running near the grease limiting speed without oil cooling",
      "indentation of both raceways by hard particles in an open, unsealed arrangement"
    ],
    "pitfalls": [
      "At 530 mm bore the 4T-4130/530UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 3750 kN C level.",
      "The 430 light plan keeps 4T-4130/530UTG narrower and faster than the 432 heavy execution of the same 530 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "Order by the full 4130/530UTG code including suffixes — U, X, DX, E1 and UTG variants share the 530 mm bore but are different articles with different internal geometry.",
      "Lubricant must reach both rows: a housing groove aligned to the cup mid-width of 4T-4130/530UTG feeds the two roller complements evenly; a single-side feed starves the far row.",
      "Open 4T-4130/530UTG units have no seals: the housing must seal both rows or the 290 r/min grease figure is meaningless once contamination enters.",
      "The 3750/5900 kN ratings and 410 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-4130/530UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-4130/530UTG?",
        "a": "4T-4130/530UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 530 mm bore, 780 mm outside diameter and 185 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 3750 kN, C0 5900 kN, Cu 410 kN, grease limiting speed 290 r/min, oil speed 420 r/min, mass about 270 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 530 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-4130/530UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-4130/530UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 185 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 4130/530UTG mean?",
        "a": "Suffix reading on 4130/530UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-4130/530UTG list two speeds, 290 and 420 r/min?",
        "a": "The lower figure, 290 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-4130/530UTG at 420 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "4130",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=200",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4130-530utg",
      "4t-4130-530utg",
      "＊4130-530utg",
      "4130-530UTG",
      "4T-4130-530UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "4130-600UTG",
    "brand": "NTN",
    "manufacturer_designation": "NTN 4T-4130/600UTG",
    "series": "4t-430-series",
    "type": "tapered_roller",
    "d_mm": 600,
    "D_mm": 870,
    "B_mm": 200,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel",
    "dynamic_load_kN": 5000,
    "static_load_kN": 8550,
    "fatigue_load_limit_kN": 570,
    "limiting_speed_rpm": 250,
    "max_rpm": 250,
    "speed_oil_rpm": 360,
    "weight_g": 350000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ANSI ABMA 19.2",
    "naming_rule_text": "The NTN 2203E double-row table prints 4T-4130/600UTG at 600 mm bore, 870 mm OD and 200 mm overall width, with a grease limiting speed of 250 r/min and an oil ceiling of 360 r/min. The 4T- prefix is NTN's tapered roller quality mark; 430 numbers the light TDO plan and 432 the heavy TDO plan — at the same 600 mm bore the 432 execution carries a wider, heavier section than the 430. Axial capacity is bidirectional because the rows are opposed: 4T-4130/600UTG locates the shaft in both directions with C0 8550 kN behind the static check of the more heavily loaded row. TDO construction means the two cone assemblies of 4T-4130/600UTG face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 600 mm shaft. Induction heating to max 120 °C is the standard fitting method at this 600 mm bore; driving the unit home through the rollers brinells both rows at once.",
    "applications": [
      "mine hoist and dragline drum shafts",
      "cement-plant mill and kiln drive trains",
      "port-crane hoist and luffing gearboxes",
      "heavy press and forging-machine drives"
    ],
    "failure_modes": [
      "roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant",
      "brinelling of both rows from a mounting blow transmitted through the roller complements",
      "preload loss and hammering noise when the cup clamping loosens and the unit gains axial float",
      "pressed-steel cage pocket wear from roller skid at light load and high speed",
      "water-induced pitting when washdown reaches the open unit without external seals"
    ],
    "pitfalls": [
      "At 600 mm bore the 4T-4130/600UTG unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 5000 kN C level.",
      "The 430 light plan keeps 4T-4130/600UTG narrower and faster than the 432 heavy execution of the same 600 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.",
      "An unloaded 4T-4130/600UTG near 250 r/min lets rollers skid; ensure a minimum load or light spring preload on high-speed positions.",
      "At inspection do not mix the cone assemblies of 4T-4130/600UTG with another unit; rows are ground together and re-matching is not guaranteed in the field.",
      "Clamping the double cup with a cocked end cover pinches one row: tighten the 870 mm OD clamping uniformly around the circumference.",
      "The 5000/8550 kN ratings and 570 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-4130/600UTG; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 4T-4130/600UTG?",
        "a": "4T-4130/600UTG is a double-row tapered roller bearing of TDO (back-to-back) construction: 600 mm bore, 870 mm outside diameter and 200 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 5000 kN, C0 8550 kN, Cu 570 kN, grease limiting speed 250 r/min, oil speed 360 r/min, mass about 350 kg. It is an open, preset-clearance unit with pressed-steel cages."
      },
      {
        "q": "What is the difference between the NTN 430 and 432 double-row series at 600 mm bore?",
        "a": "Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-4130/600UTG belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family)."
      },
      {
        "q": "Can the internal clearance of 4T-4130/600UTG be adjusted at mounting?",
        "a": "No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 200 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row."
      },
      {
        "q": "What do the suffix letters on 4130/600UTG mean?",
        "a": "Suffix reading on 4130/600UTG: UTG marks the ULTAGE specification for large NTN tapered rollers — upgraded material and internal design, printed with the ＊ symbol ahead of the order number; suffixed variants are separate order numbers and are not interchangeable articles."
      },
      {
        "q": "Why does 4T-4130/600UTG list two speeds, 250 and 360 r/min?",
        "a": "The lower figure, 250 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-4130/600UTG at 360 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "4130",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=200",
    "catalog_ver": "NTN 2203E 2026-09-25",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "4130-600utg",
      "4t-4130-600utg",
      "＊4130-600utg",
      "4130-600UTG",
      "4T-4130-600UTG"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7000-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7000",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 10,
    "D_mm": 26,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 5.1,
    "static_load_kN": 2.07,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.16,
    "limiting_speed_rpm": 29000,
    "max_rpm": 29000,
    "speed_oil_rpm": 39000,
    "weight_g": 23,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The standard-section 7000 single-row family entry 7000 carries a 10 mm bore in a 26 mm outside diameter, 8 mm wide envelope. Reading the code: 70 is the single-row dimension series (standard-section 7000 single-row family), 00 encodes the 10 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The static margin, C0 2.07 kN versus C 5.1 kN, is what supports slow oscillating duty and shock without immediate brinelling. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 10 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Do not pair two random 7000 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "On a 10 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Do not pair two random 7000 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 5.1/2.07 kN ratings and 0.16 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7000; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7000?",
        "a": "7000 is a single-row angular contact ball bearing to ISO 15: 10 mm bore, 26 mm outside diameter, 8 mm width (0.394 x 1.024 x 0.315 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 5.1 kN, C0 2.07 kN and a 0.16 kN fatigue load limit Pu; the grease limiting speed is 29,000 r/min and the oil rating 39,000 r/min; mass about 23 g."
      },
      {
        "q": "How is the 7000 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 00 encodes the 10 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 26 mm OD and 8 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7000 support?",
        "a": "One 7000 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7000?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 29,000 r/min and the oil rating 39,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7000?",
        "a": "The 10/26/8 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 5.1 kN / C0 2.07 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7000",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7000",
      "7000-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5200S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5200S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 10,
    "D_mm": 30,
    "B_mm": 14.3,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 7.15,
    "static_load_kN": 3.9,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.23,
    "limiting_speed_rpm": 17000,
    "max_rpm": 17000,
    "speed_oil_rpm": 22000,
    "weight_g": 50,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 5200S double-row family, 5200S measures 10 mm across the bore, 30 mm over the outer ring and 14.3 mm across the faces. NTN builds the number from 52 is the double-row dimension series (medium-duty 5200S double-row family), then 00 encodes the 10 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. With C 7.15 kN and C0 3.9 kN, each mm of bore carries about 0.72 kN of dynamic rating. Size selection is usually finished by checking that the C0 of 3.9 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At 10 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "The 17,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "A 5200S mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "On a 10 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 7.15/3.9 kN ratings and 0.23 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5200S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5200S?",
        "a": "5200S is a double-row angular contact ball bearing to ISO 15: 10 mm bore, 30 mm outside diameter, 14.3 mm width (0.394 x 1.181 x 0.563 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 7.15 kN, C0 3.9 kN and a 0.23 kN fatigue load limit Pu; the grease limiting speed is 17,000 r/min and the oil rating 22,000 r/min; mass about 50 g."
      },
      {
        "q": "How is the 5200S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 00 encodes the 10 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 30 mm OD and 14.3 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5200S support?",
        "a": "5200S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5200S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 17,000 r/min and the oil rating 22,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5200S?",
        "a": "The 10/30/14.3 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 7.15 kN / C0 3.9 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5200S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5200s",
      "5200S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5200SCLLD",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5200SCLLD",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 10,
    "D_mm": 30,
    "B_mm": 14.3,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 7.15,
    "static_load_kN": 3.9,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.23,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "weight_g": 50,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 5200S double-row family entry 5200SCLLD carries a 10 mm bore in a 30 mm outside diameter, 14.3 mm wide envelope. Reading the code: 52 is the double-row dimension series (medium-duty 5200S double-row family), 00 encodes the 10 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The grease limiting speed is 15,000 r/min and no oil rating is printed for this execution. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Heat-mounting to 80-90 deg C is the clean route onto a 10 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 10 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLD contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Grease rated for deep-groove motor duty is not automatically right at 15,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 7.15/3.9 kN ratings and 0.23 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5200SCLLD; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5200SCLLD?",
        "a": "5200SCLLD is a sealed double-row angular contact ball bearing to ISO 15: 10 mm bore, 30 mm outside diameter, 14.3 mm width (0.394 x 1.181 x 0.563 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 7.15 kN, C0 3.9 kN and a 0.23 kN fatigue load limit Pu; the grease limiting speed is 15,000 r/min and no oil rating is printed for this execution; mass about 50 g."
      },
      {
        "q": "How is the 5200SCLLD designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 00 encodes the 10 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The 30 mm OD and 14.3 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5200SCLLD support?",
        "a": "5200SCLLD is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with contact rubber seals (grease-lubricated, no oil speed rating)."
      },
      {
        "q": "What lubrication speeds does NTN print for 5200SCLLD?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 15,000 r/min and no oil rating is printed for this execution. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5200SCLLD?",
        "a": "The 10/30/14.3 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 7.15 kN / C0 3.9 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5200SCLLD",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5200sclld",
      "5200SCLLD"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5200SCLLM",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5200SCLLM",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 10,
    "D_mm": 30,
    "B_mm": 14.3,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 7.15,
    "static_load_kN": 3.9,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.23,
    "limiting_speed_rpm": 17000,
    "max_rpm": 17000,
    "speed_oil_rpm": 22000,
    "weight_g": 50,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "5200SCLLM is the 10 mm bore member of NTN's medium-duty 5200S double-row family, with a 30 mm outside diameter and 14.3 mm section width. The designation breaks down as 52 is the double-row dimension series (medium-duty 5200S double-row family); 00 encodes the 10 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. With C 7.15 kN and C0 3.9 kN, each mm of bore carries about 0.72 kN of dynamic rating. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Grease quantity matters as much as grade at 17,000 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At 10 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLM non-contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5200SCLLM without re-checking axial float, heat and housing width — the kinematics differ.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "On a 10 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 7.15/3.9 kN ratings and 0.23 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5200SCLLM; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5200SCLLM?",
        "a": "5200SCLLM is a sealed double-row angular contact ball bearing to ISO 15: 10 mm bore, 30 mm outside diameter, 14.3 mm width (0.394 x 1.181 x 0.563 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 7.15 kN, C0 3.9 kN and a 0.23 kN fatigue load limit Pu; the grease limiting speed is 17,000 r/min and the oil rating 22,000 r/min; mass about 50 g."
      },
      {
        "q": "How is the 5200SCLLM designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 00 encodes the 10 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The 30 mm OD and 14.3 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5200SCLLM support?",
        "a": "5200SCLLM is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with non-contact rubber seals that keep the shield-level speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5200SCLLM?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 17,000 r/min and the oil rating 22,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5200SCLLM?",
        "a": "The 10/30/14.3 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 7.15 kN / C0 3.9 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5200SCLLM",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5200scllm",
      "5200SCLLM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5200SCZZ",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5200SCZZ",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 10,
    "D_mm": 30,
    "B_mm": 14.3,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 7.15,
    "static_load_kN": 3.9,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.23,
    "limiting_speed_rpm": 17000,
    "max_rpm": 17000,
    "speed_oil_rpm": 22000,
    "weight_g": 50,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 5200S double-row family, 5200SCZZ measures 10 mm across the bore, 30 mm over the outer ring and 14.3 mm across the faces. NTN builds the number from 52 is the double-row dimension series (medium-duty 5200S double-row family), then 00 encodes the 10 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. Catalogue dynamic rating C is 7.15 kN against C0 3.9 kN — a C0/C ratio of 0.55 that is typical of an angular-contact contact ellipse. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At 10 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed ZZ shielded executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5200SCZZ without re-checking axial float, heat and housing width — the kinematics differ.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 7.15/3.9 kN ratings and 0.23 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5200SCZZ; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5200SCZZ?",
        "a": "5200SCZZ is a sealed double-row angular contact ball bearing to ISO 15: 10 mm bore, 30 mm outside diameter, 14.3 mm width (0.394 x 1.181 x 0.563 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 7.15 kN, C0 3.9 kN and a 0.23 kN fatigue load limit Pu; the grease limiting speed is 17,000 r/min and the oil rating 22,000 r/min; mass about 50 g."
      },
      {
        "q": "How is the 5200SCZZ designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 00 encodes the 10 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The 30 mm OD and 14.3 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5200SCZZ support?",
        "a": "5200SCZZ is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with pressed-steel shields that keep the open-bearing speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5200SCZZ?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 17,000 r/min and the oil rating 22,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5200SCZZ?",
        "a": "The 10/30/14.3 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 7.15 kN / C0 3.9 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5200SCZZ",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5200sczz",
      "5200SCZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7200-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7200",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 10,
    "D_mm": 30,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 6,
    "static_load_kN": 2.74,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.21,
    "limiting_speed_rpm": 28000,
    "max_rpm": 28000,
    "speed_oil_rpm": 37000,
    "weight_g": 29,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7200 is the 10 mm bore member of NTN's medium-duty 7200 single-row family, with a 30 mm outside diameter and 9 mm section width. NTN builds the number from 72 is the single-row dimension series (medium-duty 7200 single-row family), then 00 encodes the 10 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The radial section height here is 10.0 mm, and the catalogue couples that with C 6 kN / C0 2.74 kN. For a 10 mm shaft with combined load, the practical shortlist is this series, its 7300-series heavier section, and — where thrust reverses — a back-to-back pair rather than a single row. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At 10 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A 7200 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7200 without re-checking axial float, heat and housing width — the kinematics differ.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 6/2.74 kN ratings and 0.21 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7200; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7200?",
        "a": "7200 is a single-row angular contact ball bearing to ISO 15: 10 mm bore, 30 mm outside diameter, 9 mm width (0.394 x 1.181 x 0.354 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 6 kN, C0 2.74 kN and a 0.21 kN fatigue load limit Pu; the grease limiting speed is 28,000 r/min and the oil rating 37,000 r/min; mass about 29 g."
      },
      {
        "q": "How is the 7200 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 00 encodes the 10 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 30 mm OD and 9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7200 support?",
        "a": "One 7200 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7200?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 28,000 r/min and the oil rating 37,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7200?",
        "a": "The 10/30/9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 6 kN / C0 2.74 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7200",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7200-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7200-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7200",
      "7200-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7200B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7200B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 10,
    "D_mm": 30,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 5.5,
    "static_load_kN": 2.52,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.2,
    "limiting_speed_rpm": 24000,
    "max_rpm": 24000,
    "speed_oil_rpm": 32000,
    "weight_g": 29,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 7200 single-row family entry 7200B carries a 10 mm bore in a 30 mm outside diameter, 9 mm wide envelope. Decoding 7200B: 72 is the single-row dimension series (medium-duty 7200 single-row family), with 00 encodes the 10 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The radial section height here is 10.0 mm, and the catalogue couples that with C 5.5 kN / C0 2.52 kN. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Heat-mounting to 80-90 deg C is the clean route onto a 10 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At 10 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Do not pair two random 7200B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 5.5/2.52 kN ratings and 0.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7200B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7200B?",
        "a": "7200B is a single-row angular contact ball bearing to ISO 15: 10 mm bore, 30 mm outside diameter, 9 mm width (0.394 x 1.181 x 0.354 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 5.5 kN, C0 2.52 kN and a 0.2 kN fatigue load limit Pu; the grease limiting speed is 24,000 r/min and the oil rating 32,000 r/min; mass about 29 g."
      },
      {
        "q": "How is the 7200B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 00 encodes the 10 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 30 mm OD and 9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7200B support?",
        "a": "One 7200B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7200B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 24,000 r/min and the oil rating 32,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7200B?",
        "a": "The 10/30/9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 5.5 kN / C0 2.52 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7200B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7200b",
      "7200B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7300-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7300",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 10,
    "D_mm": 35,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 11.2,
    "static_load_kN": 4.95,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.39,
    "limiting_speed_rpm": 26000,
    "max_rpm": 26000,
    "speed_oil_rpm": 34000,
    "weight_g": 40,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 10 x 35 x 11 mm, NTN 7300 sits in the heavy-duty 7300 single-row family of the angular-contact programme. Decoding 7300: 73 is the single-row dimension series (heavy-duty 7300 single-row family), with 00 encodes the 10 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue mass is about 40 g, which at this 12.5 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Heat-mounting to 80-90 deg C is the clean route onto a 10 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At 10 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Grease rated for deep-groove motor duty is not automatically right at 26,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Grease rated for deep-groove motor duty is not automatically right at 26,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 11.2/4.95 kN ratings and 0.39 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7300; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7300?",
        "a": "7300 is a single-row angular contact ball bearing to ISO 15: 10 mm bore, 35 mm outside diameter, 11 mm width (0.394 x 1.378 x 0.433 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 11.2 kN, C0 4.95 kN and a 0.39 kN fatigue load limit Pu; the grease limiting speed is 26,000 r/min and the oil rating 34,000 r/min; mass about 40 g."
      },
      {
        "q": "How is the 7300 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 00 encodes the 10 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 35 mm OD and 11 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7300 support?",
        "a": "One 7300 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7300?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 26,000 r/min and the oil rating 34,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7300?",
        "a": "The 10/35/11 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 11.2 kN / C0 4.95 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7300",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7300",
      "7300-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7300B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7300B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 10,
    "D_mm": 35,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 10.5,
    "static_load_kN": 4.6,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.36,
    "limiting_speed_rpm": 22000,
    "max_rpm": 22000,
    "speed_oil_rpm": 29000,
    "weight_g": 41,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7300B appears as a heavy-duty 7300 single-row family bearing of 10 mm bore, 35 mm outside diameter and 11 mm width. Reading the code: 73 is the single-row dimension series (heavy-duty 7300 single-row family), 00 encodes the 10 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Heat-mounting to 80-90 deg C is the clean route onto a 10 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 10 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7300B without re-checking axial float, heat and housing width — the kinematics differ.",
      "The C0 of 4.6 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 22,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 10.5/4.6 kN ratings and 0.36 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7300B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7300B?",
        "a": "7300B is a single-row angular contact ball bearing to ISO 15: 10 mm bore, 35 mm outside diameter, 11 mm width (0.394 x 1.378 x 0.433 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 10.5 kN, C0 4.6 kN and a 0.36 kN fatigue load limit Pu; the grease limiting speed is 22,000 r/min and the oil rating 29,000 r/min; mass about 41 g."
      },
      {
        "q": "How is the 7300B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 00 encodes the 10 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 35 mm OD and 11 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7300B support?",
        "a": "One 7300B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7300B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 22,000 r/min and the oil rating 29,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7300B?",
        "a": "The 10/35/11 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 10.5 kN / C0 4.6 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7300B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7300b",
      "7300B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7001-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7001",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 12,
    "D_mm": 28,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 5.6,
    "static_load_kN": 2.46,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.19,
    "limiting_speed_rpm": 26000,
    "max_rpm": 26000,
    "speed_oil_rpm": 35000,
    "weight_g": 25,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 12 x 28 x 8 mm, NTN 7001 sits in the standard-section 7000 single-row family of the angular-contact programme. Decoding 7001: 70 is the single-row dimension series (standard-section 7000 single-row family), with 01 encodes the 12 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The oil rating of 35,000 r/min sits 9,000 r/min above the 26,000 r/min grease figure — a 1.35x step that says how much headroom oil cooling buys. Size selection is usually finished by checking that the C0 of 2.46 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At 12 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "A 7001 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Grease rated for deep-groove motor duty is not automatically right at 26,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 5.6/2.46 kN ratings and 0.19 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7001; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7001?",
        "a": "7001 is a single-row angular contact ball bearing to ISO 15: 12 mm bore, 28 mm outside diameter, 8 mm width (0.472 x 1.102 x 0.315 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 5.6 kN, C0 2.46 kN and a 0.19 kN fatigue load limit Pu; the grease limiting speed is 26,000 r/min and the oil rating 35,000 r/min; mass about 25 g."
      },
      {
        "q": "How is the 7001 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 01 encodes the 12 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 28 mm OD and 8 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7001 support?",
        "a": "One 7001 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7001?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 26,000 r/min and the oil rating 35,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7001?",
        "a": "The 12/28/8 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 5.6 kN / C0 2.46 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7001",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7001",
      "7001-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5201S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5201S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 12,
    "D_mm": 32,
    "B_mm": 15.9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 10.5,
    "static_load_kN": 5.8,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.35,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "speed_oil_rpm": 20000,
    "weight_g": 60,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 5201S belongs to the medium-duty 5200S double-row family: the catalogue boundary dimensions read 12 / 32 / 15.9 mm (bore / OD / width). Reading the code: 52 is the double-row dimension series (medium-duty 5200S double-row family), 01 encodes the 12 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The oil rating of 20,000 r/min sits 5,000 r/min above the 15,000 r/min grease figure — a 1.33x step that says how much headroom oil cooling buys. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Heat-mounting to 80-90 deg C is the clean route onto a 12 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 12 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Do not pair two random 5201S bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Grease rated for deep-groove motor duty is not automatically right at 15,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 10.5/5.8 kN ratings and 0.35 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5201S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5201S?",
        "a": "5201S is a double-row angular contact ball bearing to ISO 15: 12 mm bore, 32 mm outside diameter, 15.9 mm width (0.472 x 1.26 x 0.626 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 10.5 kN, C0 5.8 kN and a 0.35 kN fatigue load limit Pu; the grease limiting speed is 15,000 r/min and the oil rating 20,000 r/min; mass about 60 g."
      },
      {
        "q": "How is the 5201S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 01 encodes the 12 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 32 mm OD and 15.9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5201S support?",
        "a": "5201S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5201S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 15,000 r/min and the oil rating 20,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5201S?",
        "a": "The 12/32/15.9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 10.5 kN / C0 5.8 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5201S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5201s",
      "5201S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5201SCLLD",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5201SCLLD",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 12,
    "D_mm": 32,
    "B_mm": 15.9,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 8.5,
    "static_load_kN": 5.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.31,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 60,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 5200S double-row family entry 5201SCLLD carries a 12 mm bore in a 32 mm outside diameter, 15.9 mm wide envelope. Two fields make up the code — 52 is the double-row dimension series (medium-duty 5200S double-row family) and 01 encodes the 12 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The radial section height here is 10.0 mm, and the catalogue couples that with C 8.5 kN / C0 5.3 kN. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Grease quantity matters as much as grade at 12,000 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At 12 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLD contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 8.5/5.3 kN ratings and 0.31 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5201SCLLD; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5201SCLLD?",
        "a": "5201SCLLD is a sealed double-row angular contact ball bearing to ISO 15: 12 mm bore, 32 mm outside diameter, 15.9 mm width (0.472 x 1.26 x 0.626 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 8.5 kN, C0 5.3 kN and a 0.31 kN fatigue load limit Pu; the grease limiting speed is 12,000 r/min and no oil rating is printed for this execution; mass about 60 g."
      },
      {
        "q": "How is the 5201SCLLD designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 01 encodes the 12 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The 32 mm OD and 15.9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5201SCLLD support?",
        "a": "5201SCLLD is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with contact rubber seals (grease-lubricated, no oil speed rating)."
      },
      {
        "q": "What lubrication speeds does NTN print for 5201SCLLD?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 12,000 r/min and no oil rating is printed for this execution. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5201SCLLD?",
        "a": "The 12/32/15.9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 8.5 kN / C0 5.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5201SCLLD",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5201sclld",
      "5201SCLLD"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5201SCLLM",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5201SCLLM",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 12,
    "D_mm": 32,
    "B_mm": 15.9,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 8.5,
    "static_load_kN": 5.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.31,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "speed_oil_rpm": 20000,
    "weight_g": 60,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "5201SCLLM is the 12 mm bore member of NTN's medium-duty 5200S double-row family, with a 32 mm outside diameter and 15.9 mm section width. Reading the code: 52 is the double-row dimension series (medium-duty 5200S double-row family), 01 encodes the 12 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. A 12 mm shaft typically takes a j5/k5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 12 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLM non-contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "A 5201SCLLM mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The C0 of 5.3 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 15,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 8.5/5.3 kN ratings and 0.31 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5201SCLLM; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5201SCLLM?",
        "a": "5201SCLLM is a sealed double-row angular contact ball bearing to ISO 15: 12 mm bore, 32 mm outside diameter, 15.9 mm width (0.472 x 1.26 x 0.626 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 8.5 kN, C0 5.3 kN and a 0.31 kN fatigue load limit Pu; the grease limiting speed is 15,000 r/min and the oil rating 20,000 r/min; mass about 60 g."
      },
      {
        "q": "How is the 5201SCLLM designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 01 encodes the 12 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The 32 mm OD and 15.9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5201SCLLM support?",
        "a": "5201SCLLM is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with non-contact rubber seals that keep the shield-level speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5201SCLLM?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 15,000 r/min and the oil rating 20,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5201SCLLM?",
        "a": "The 12/32/15.9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 8.5 kN / C0 5.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5201SCLLM",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5201scllm",
      "5201SCLLM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5201SCZZ",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5201SCZZ",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 12,
    "D_mm": 32,
    "B_mm": 15.9,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 8.5,
    "static_load_kN": 5.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.31,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "speed_oil_rpm": 20000,
    "weight_g": 60,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "5201SCZZ is an NTN sealed double-row angular contact ball bearing: medium-duty 5200S double-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 12 x 32 x 15.9 mm. Reading the code: 52 is the double-row dimension series (medium-duty 5200S double-row family), 01 encodes the 12 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. At roughly 10.0 mm of radial section, the catalogue still quotes 8.5 kN dynamic capacity for the 12 mm bore. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 12 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed ZZ shielded executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "On a 12 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 8.5/5.3 kN ratings and 0.31 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5201SCZZ; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5201SCZZ?",
        "a": "5201SCZZ is a sealed double-row angular contact ball bearing to ISO 15: 12 mm bore, 32 mm outside diameter, 15.9 mm width (0.472 x 1.26 x 0.626 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 8.5 kN, C0 5.3 kN and a 0.31 kN fatigue load limit Pu; the grease limiting speed is 15,000 r/min and the oil rating 20,000 r/min; mass about 60 g."
      },
      {
        "q": "How is the 5201SCZZ designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 01 encodes the 12 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The 32 mm OD and 15.9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5201SCZZ support?",
        "a": "5201SCZZ is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with pressed-steel shields that keep the open-bearing speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5201SCZZ?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 15,000 r/min and the oil rating 20,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5201SCZZ?",
        "a": "The 12/32/15.9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 8.5 kN / C0 5.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5201SCZZ",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5201sczz",
      "5201SCZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7201-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7201",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 12,
    "D_mm": 32,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 8.4,
    "static_load_kN": 3.95,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.31,
    "limiting_speed_rpm": 25000,
    "max_rpm": 25000,
    "speed_oil_rpm": 33000,
    "weight_g": 35,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 12 x 32 x 10 mm, NTN 7201 sits in the medium-duty 7200 single-row family of the angular-contact programme. Reading the code: 72 is the single-row dimension series (medium-duty 7200 single-row family), 01 encodes the 12 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. On speed, the grease limiting speed is 25,000 r/min and the oil rating 33,000 r/min. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Heat-mounting to 80-90 deg C is the clean route onto a 12 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 12 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7201 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The C0 of 3.95 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 8.4/3.95 kN ratings and 0.31 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7201; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7201?",
        "a": "7201 is a single-row angular contact ball bearing to ISO 15: 12 mm bore, 32 mm outside diameter, 10 mm width (0.472 x 1.26 x 0.394 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 8.4 kN, C0 3.95 kN and a 0.31 kN fatigue load limit Pu; the grease limiting speed is 25,000 r/min and the oil rating 33,000 r/min; mass about 35 g."
      },
      {
        "q": "How is the 7201 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 01 encodes the 12 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 32 mm OD and 10 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7201 support?",
        "a": "One 7201 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7201?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 25,000 r/min and the oil rating 33,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7201?",
        "a": "The 12/32/10 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 8.4 kN / C0 3.95 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7201",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7201-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7201-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7201",
      "7201-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7201B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7201B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 12,
    "D_mm": 32,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 7.75,
    "static_load_kN": 3.65,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.29,
    "limiting_speed_rpm": 21000,
    "max_rpm": 21000,
    "speed_oil_rpm": 28000,
    "weight_g": 36,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 7200 single-row family, 7201B measures 12 mm across the bore, 32 mm over the outer ring and 10 mm across the faces. The designation breaks down as 72 is the single-row dimension series (medium-duty 7200 single-row family); 01 encodes the 12 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). On speed, the grease limiting speed is 21,000 r/min and the oil rating 28,000 r/min. The 12/32/10 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 12 mm bore give the working limits. ",
    "applications": [
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At 12 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "The 21,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The C0 of 3.65 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 7.75/3.65 kN ratings and 0.29 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7201B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7201B?",
        "a": "7201B is a single-row angular contact ball bearing to ISO 15: 12 mm bore, 32 mm outside diameter, 10 mm width (0.472 x 1.26 x 0.394 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 7.75 kN, C0 3.65 kN and a 0.29 kN fatigue load limit Pu; the grease limiting speed is 21,000 r/min and the oil rating 28,000 r/min; mass about 36 g."
      },
      {
        "q": "How is the 7201B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 01 encodes the 12 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 32 mm OD and 10 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7201B support?",
        "a": "One 7201B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7201B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 21,000 r/min and the oil rating 28,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7201B?",
        "a": "The 12/32/10 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 7.75 kN / C0 3.65 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7201B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7201b",
      "7201B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7301-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7301",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 12,
    "D_mm": 37,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 12.4,
    "static_load_kN": 5.25,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.41,
    "limiting_speed_rpm": 23000,
    "max_rpm": 23000,
    "speed_oil_rpm": 30000,
    "weight_g": 44,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7301 is the 12 mm bore member of NTN's heavy-duty 7300 single-row family, with a 37 mm outside diameter and 12 mm section width. The designation breaks down as 73 is the single-row dimension series (heavy-duty 7300 single-row family); 01 encodes the 12 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The radial section height here is 12.5 mm, and the catalogue couples that with C 12.4 kN / C0 5.25 kN. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Heat-mounting to 80-90 deg C is the clean route onto a 12 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At 12 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A 7301 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "On a 12 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 12.4/5.25 kN ratings and 0.41 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7301; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7301?",
        "a": "7301 is a single-row angular contact ball bearing to ISO 15: 12 mm bore, 37 mm outside diameter, 12 mm width (0.472 x 1.457 x 0.472 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 12.4 kN, C0 5.25 kN and a 0.41 kN fatigue load limit Pu; the grease limiting speed is 23,000 r/min and the oil rating 30,000 r/min; mass about 44 g."
      },
      {
        "q": "How is the 7301 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 01 encodes the 12 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 37 mm OD and 12 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7301 support?",
        "a": "One 7301 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7301?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 23,000 r/min and the oil rating 30,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7301?",
        "a": "The 12/37/12 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 12.4 kN / C0 5.25 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7301",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7301-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7301-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7301",
      "7301-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7301B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7301B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 12,
    "D_mm": 37,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 11.7,
    "static_load_kN": 4.95,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.39,
    "limiting_speed_rpm": 19000,
    "max_rpm": 19000,
    "speed_oil_rpm": 26000,
    "weight_g": 45,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 12 x 37 x 12 mm, NTN 7301B sits in the heavy-duty 7300 single-row family of the angular-contact programme. Decoding 7301B: 73 is the single-row dimension series (heavy-duty 7300 single-row family), with 01 encodes the 12 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The radial section height here is 12.5 mm, and the catalogue couples that with C 11.7 kN / C0 4.95 kN. Choose the heavy-duty 7300 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 12 mm bore give the working limits. ",
    "applications": [
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At 12 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Grease rated for deep-groove motor duty is not automatically right at 19,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 11.7/4.95 kN ratings and 0.39 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7301B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7301B?",
        "a": "7301B is a single-row angular contact ball bearing to ISO 15: 12 mm bore, 37 mm outside diameter, 12 mm width (0.472 x 1.457 x 0.472 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 11.7 kN, C0 4.95 kN and a 0.39 kN fatigue load limit Pu; the grease limiting speed is 19,000 r/min and the oil rating 26,000 r/min; mass about 45 g."
      },
      {
        "q": "How is the 7301B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 01 encodes the 12 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 37 mm OD and 12 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7301B support?",
        "a": "One 7301B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7301B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 19,000 r/min and the oil rating 26,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7301B?",
        "a": "The 12/37/12 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 11.7 kN / C0 4.95 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7301B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7301b",
      "7301B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7002-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7002",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 15,
    "D_mm": 32,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 6.4,
    "static_load_kN": 3.15,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.25,
    "limiting_speed_rpm": 23000,
    "max_rpm": 23000,
    "speed_oil_rpm": 31000,
    "weight_g": 35,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7002 is the 15 mm bore member of NTN's standard-section 7000 single-row family, with a 32 mm outside diameter and 9 mm section width. The designation breaks down as 70 is the single-row dimension series (standard-section 7000 single-row family); 02 encodes the 15 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue dynamic rating C is 6.4 kN against C0 3.15 kN — a C0/C ratio of 0.49 that is typical of an angular-contact contact ellipse. The 15/32/9 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At 15 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 6.4/3.15 kN ratings and 0.25 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7002; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7002?",
        "a": "7002 is a single-row angular contact ball bearing to ISO 15: 15 mm bore, 32 mm outside diameter, 9 mm width (0.591 x 1.26 x 0.354 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 6.4 kN, C0 3.15 kN and a 0.25 kN fatigue load limit Pu; the grease limiting speed is 23,000 r/min and the oil rating 31,000 r/min; mass about 35 g."
      },
      {
        "q": "How is the 7002 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 02 encodes the 15 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 32 mm OD and 9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7002 support?",
        "a": "One 7002 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7002?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 23,000 r/min and the oil rating 31,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7002?",
        "a": "The 15/32/9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 6.4 kN / C0 3.15 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7002",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7002",
      "7002-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5202S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5202S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 15,
    "D_mm": 35,
    "B_mm": 15.9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 11.7,
    "static_load_kN": 7.05,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.42,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "speed_oil_rpm": 17000,
    "weight_g": 70,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "5202S is the 15 mm bore member of NTN's medium-duty 5200S double-row family, with a 35 mm outside diameter and 15.9 mm section width. Decoding 5202S: 52 is the double-row dimension series (medium-duty 5200S double-row family), with 02 encodes the 15 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. At roughly 10.0 mm of radial section, the catalogue still quotes 11.7 kN dynamic capacity for the 15 mm bore. Choose the medium-duty 5200S double-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 15 mm bore give the working limits. ",
    "applications": [
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At 15 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "Grease rated for deep-groove motor duty is not automatically right at 13,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 11.7/7.05 kN ratings and 0.42 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5202S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5202S?",
        "a": "5202S is a double-row angular contact ball bearing to ISO 15: 15 mm bore, 35 mm outside diameter, 15.9 mm width (0.591 x 1.378 x 0.626 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 11.7 kN, C0 7.05 kN and a 0.42 kN fatigue load limit Pu; the grease limiting speed is 13,000 r/min and the oil rating 17,000 r/min; mass about 70 g."
      },
      {
        "q": "How is the 5202S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 02 encodes the 15 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 35 mm OD and 15.9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5202S support?",
        "a": "5202S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5202S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 13,000 r/min and the oil rating 17,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5202S?",
        "a": "The 15/35/15.9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 11.7 kN / C0 7.05 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5202S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5202s",
      "5202S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5202SCLLD",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5202SCLLD",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 15,
    "D_mm": 35,
    "B_mm": 15.9,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 8.5,
    "static_load_kN": 5.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.31,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 70,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5202SCLLD appears as a medium-duty 5200S double-row family bearing of 15 mm bore, 35 mm outside diameter and 15.9 mm width. Reading the code: 52 is the double-row dimension series (medium-duty 5200S double-row family), 02 encodes the 15 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. With C 8.5 kN and C0 5.3 kN, each mm of bore carries about 0.57 kN of dynamic rating. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Grease quantity matters as much as grade at 12,000 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 15 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLD contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5202SCLLD without re-checking axial float, heat and housing width — the kinematics differ.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "On a 15 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 8.5/5.3 kN ratings and 0.31 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5202SCLLD; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5202SCLLD?",
        "a": "5202SCLLD is a sealed double-row angular contact ball bearing to ISO 15: 15 mm bore, 35 mm outside diameter, 15.9 mm width (0.591 x 1.378 x 0.626 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 8.5 kN, C0 5.3 kN and a 0.31 kN fatigue load limit Pu; the grease limiting speed is 12,000 r/min and no oil rating is printed for this execution; mass about 70 g."
      },
      {
        "q": "How is the 5202SCLLD designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 02 encodes the 15 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The 35 mm OD and 15.9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5202SCLLD support?",
        "a": "5202SCLLD is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with contact rubber seals (grease-lubricated, no oil speed rating)."
      },
      {
        "q": "What lubrication speeds does NTN print for 5202SCLLD?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 12,000 r/min and no oil rating is printed for this execution. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5202SCLLD?",
        "a": "The 15/35/15.9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 8.5 kN / C0 5.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5202SCLLD",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5202sclld",
      "5202SCLLD"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5202SCLLM",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5202SCLLM",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 15,
    "D_mm": 35,
    "B_mm": 15.9,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 8.5,
    "static_load_kN": 5.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.31,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "speed_oil_rpm": 17000,
    "weight_g": 70,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 5200S double-row family entry 5202SCLLM carries a 15 mm bore in a 35 mm outside diameter, 15.9 mm wide envelope. The designation breaks down as 52 is the double-row dimension series (medium-duty 5200S double-row family); 02 encodes the 15 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The built-in back-to-back contact lines give the double-row bearing its two-direction thrust and moment capacity from one ring set. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. A 15 mm shaft typically takes a j5/k5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At 15 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLM non-contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "The 13,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "A 5202SCLLM mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "A 5202SCLLM mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 8.5/5.3 kN ratings and 0.31 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5202SCLLM; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5202SCLLM?",
        "a": "5202SCLLM is a sealed double-row angular contact ball bearing to ISO 15: 15 mm bore, 35 mm outside diameter, 15.9 mm width (0.591 x 1.378 x 0.626 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 8.5 kN, C0 5.3 kN and a 0.31 kN fatigue load limit Pu; the grease limiting speed is 13,000 r/min and the oil rating 17,000 r/min; mass about 70 g."
      },
      {
        "q": "How is the 5202SCLLM designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 02 encodes the 15 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The 35 mm OD and 15.9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5202SCLLM support?",
        "a": "5202SCLLM is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with non-contact rubber seals that keep the shield-level speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5202SCLLM?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 13,000 r/min and the oil rating 17,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5202SCLLM?",
        "a": "The 15/35/15.9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 8.5 kN / C0 5.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5202SCLLM",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5202scllm",
      "5202SCLLM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5202SCZZ",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5202SCZZ",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 15,
    "D_mm": 35,
    "B_mm": 15.9,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 8.5,
    "static_load_kN": 5.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.31,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "speed_oil_rpm": 17000,
    "weight_g": 70,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5202SCZZ appears as a medium-duty 5200S double-row family bearing of 15 mm bore, 35 mm outside diameter and 15.9 mm width. Decoding 5202SCZZ: 52 is the double-row dimension series (medium-duty 5200S double-row family), with 02 encodes the 15 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. NTN prints 8.5 kN dynamic and 5.3 kN static for this size and a 0.31 kN fatigue load limit Pu. For a 15 mm shaft with combined load, the practical shortlist is this series, its neighbouring dimension series, and — where thrust reverses — a back-to-back pair rather than a single row. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At 15 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed ZZ shielded executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Do not pair two random 5202SCZZ bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5202SCZZ without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 8.5/5.3 kN ratings and 0.31 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5202SCZZ; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5202SCZZ?",
        "a": "5202SCZZ is a sealed double-row angular contact ball bearing to ISO 15: 15 mm bore, 35 mm outside diameter, 15.9 mm width (0.591 x 1.378 x 0.626 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 8.5 kN, C0 5.3 kN and a 0.31 kN fatigue load limit Pu; the grease limiting speed is 13,000 r/min and the oil rating 17,000 r/min; mass about 70 g."
      },
      {
        "q": "How is the 5202SCZZ designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 02 encodes the 15 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The 35 mm OD and 15.9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5202SCZZ support?",
        "a": "5202SCZZ is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with pressed-steel shields that keep the open-bearing speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5202SCZZ?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 13,000 r/min and the oil rating 17,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5202SCZZ?",
        "a": "The 15/35/15.9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 8.5 kN / C0 5.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5202SCZZ",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5202sczz",
      "5202SCZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7202-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7202",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 15,
    "D_mm": 35,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 10,
    "static_load_kN": 4.7,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.37,
    "limiting_speed_rpm": 22000,
    "max_rpm": 22000,
    "speed_oil_rpm": 29000,
    "weight_g": 46,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7202 is the 15 mm bore member of NTN's medium-duty 7200 single-row family, with a 35 mm outside diameter and 11 mm section width. Decoding 7202: 72 is the single-row dimension series (medium-duty 7200 single-row family), with 02 encodes the 15 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. With C 10 kN and C0 4.7 kN, each mm of bore carries about 0.67 kN of dynamic rating. Against a deep-groove bearing of the same 15 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Heat-mounting to 80-90 deg C is the clean route onto a 15 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At 15 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Do not pair two random 7202 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Do not pair two random 7202 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "On a 15 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 10/4.7 kN ratings and 0.37 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7202; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7202?",
        "a": "7202 is a single-row angular contact ball bearing to ISO 15: 15 mm bore, 35 mm outside diameter, 11 mm width (0.591 x 1.378 x 0.433 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 10 kN, C0 4.7 kN and a 0.37 kN fatigue load limit Pu; the grease limiting speed is 22,000 r/min and the oil rating 29,000 r/min; mass about 46 g."
      },
      {
        "q": "How is the 7202 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 02 encodes the 15 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 35 mm OD and 11 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7202 support?",
        "a": "One 7202 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7202?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 22,000 r/min and the oil rating 29,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7202?",
        "a": "The 15/35/11 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 10 kN / C0 4.7 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7202",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7202-ACCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7202-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7202-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7202-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7202",
      "7202-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7202B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7202B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 15,
    "D_mm": 35,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 9.25,
    "static_load_kN": 4.35,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.34,
    "limiting_speed_rpm": 18000,
    "max_rpm": 18000,
    "speed_oil_rpm": 25000,
    "weight_g": 46,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7202B belongs to the medium-duty 7200 single-row family: the catalogue boundary dimensions read 15 / 35 / 11 mm (bore / OD / width). Two fields make up the code — 72 is the single-row dimension series (medium-duty 7200 single-row family) and 02 encodes the 15 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The static margin, C0 4.35 kN versus C 9.25 kN, is what supports slow oscillating duty and shock without immediate brinelling. Size selection is usually finished by checking that the C0 of 4.35 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At 15 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Do not pair two random 7202B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 9.25/4.35 kN ratings and 0.34 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7202B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7202B?",
        "a": "7202B is a single-row angular contact ball bearing to ISO 15: 15 mm bore, 35 mm outside diameter, 11 mm width (0.591 x 1.378 x 0.433 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 9.25 kN, C0 4.35 kN and a 0.34 kN fatigue load limit Pu; the grease limiting speed is 18,000 r/min and the oil rating 25,000 r/min; mass about 46 g."
      },
      {
        "q": "How is the 7202B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 02 encodes the 15 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 35 mm OD and 11 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7202B support?",
        "a": "One 7202B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7202B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 18,000 r/min and the oil rating 25,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7202B?",
        "a": "The 15/35/11 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 9.25 kN / C0 4.35 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7202B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7202b",
      "7202B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5302S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5302S",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 15,
    "D_mm": 42,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 17.6,
    "static_load_kN": 10.2,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.62,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "speed_oil_rpm": 15000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The heavy-duty 5300S double-row family entry 5302S carries a 15 mm bore in a 42 mm outside diameter, 19 mm wide envelope. Reading the code: 53 is the double-row dimension series (heavy-duty 5300S double-row family), 02 encodes the 15 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The oil rating of 15,000 r/min sits 4,000 r/min above the 11,000 r/min grease figure — a 1.36x step that says how much headroom oil cooling buys. For a 15 mm shaft with combined load, the practical shortlist is this series, its neighbouring dimension series, and — where thrust reverses — a back-to-back pair rather than a single row. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 15 mm bore give the working limits. ",
    "applications": [
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 15 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "The C0 of 10.2 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Grease rated for deep-groove motor duty is not automatically right at 11,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Grease rated for deep-groove motor duty is not automatically right at 11,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 17.6/10.2 kN ratings and 0.62 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5302S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5302S?",
        "a": "5302S is a double-row angular contact ball bearing to ISO 15: 15 mm bore, 42 mm outside diameter, 19 mm width (0.591 x 1.654 x 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 17.6 kN, C0 10.2 kN and a 0.62 kN fatigue load limit Pu; the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min; mass about 130 g."
      },
      {
        "q": "How is the 5302S designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 02 encodes the 15 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 42 mm OD and 19 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5302S support?",
        "a": "5302S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5302S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5302S?",
        "a": "The 15/42/19 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 17.6 kN / C0 10.2 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5302S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5302s",
      "5302S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7302-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7302",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 15,
    "D_mm": 42,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 14.9,
    "static_load_kN": 7.2,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.56,
    "limiting_speed_rpm": 19000,
    "max_rpm": 19000,
    "speed_oil_rpm": 26000,
    "weight_g": 55,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty 7300 single-row family, 7302 measures 15 mm across the bore, 42 mm over the outer ring and 13 mm across the faces. Two fields make up the code — 73 is the single-row dimension series (heavy-duty 7300 single-row family) and 02 encodes the 15 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The oil rating of 26,000 r/min sits 7,000 r/min above the 19,000 r/min grease figure — a 1.37x step that says how much headroom oil cooling buys. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. A 15 mm shaft typically takes a j5/k5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At 15 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7302 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 19,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Grease rated for deep-groove motor duty is not automatically right at 19,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 14.9/7.2 kN ratings and 0.56 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7302; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7302?",
        "a": "7302 is a single-row angular contact ball bearing to ISO 15: 15 mm bore, 42 mm outside diameter, 13 mm width (0.591 x 1.654 x 0.512 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 14.9 kN, C0 7.2 kN and a 0.56 kN fatigue load limit Pu; the grease limiting speed is 19,000 r/min and the oil rating 26,000 r/min; mass about 55 g."
      },
      {
        "q": "How is the 7302 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 02 encodes the 15 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 42 mm OD and 13 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7302 support?",
        "a": "One 7302 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7302?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 19,000 r/min and the oil rating 26,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7302?",
        "a": "The 15/42/13 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 14.9 kN / C0 7.2 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7302",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7302-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7302-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7302-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7302",
      "7302-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7302B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7302B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 15,
    "D_mm": 42,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 13.8,
    "static_load_kN": 6.65,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.52,
    "limiting_speed_rpm": 17000,
    "max_rpm": 17000,
    "speed_oil_rpm": 22000,
    "weight_g": 57,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7302B is an NTN single-row angular contact ball bearing: heavy-duty 7300 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 15 x 42 x 13 mm. The designation breaks down as 73 is the single-row dimension series (heavy-duty 7300 single-row family); 02 encodes the 15 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). On speed, the grease limiting speed is 17,000 r/min and the oil rating 22,000 r/min. Against a deep-groove bearing of the same 15 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At 15 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Do not pair two random 7302B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7302B without re-checking axial float, heat and housing width — the kinematics differ.",
      "The C0 of 6.65 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 13.8/6.65 kN ratings and 0.52 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7302B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7302B?",
        "a": "7302B is a single-row angular contact ball bearing to ISO 15: 15 mm bore, 42 mm outside diameter, 13 mm width (0.591 x 1.654 x 0.512 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 13.8 kN, C0 6.65 kN and a 0.52 kN fatigue load limit Pu; the grease limiting speed is 17,000 r/min and the oil rating 22,000 r/min; mass about 57 g."
      },
      {
        "q": "How is the 7302B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 02 encodes the 15 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 42 mm OD and 13 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7302B support?",
        "a": "One 7302B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7302B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 17,000 r/min and the oil rating 22,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7302B?",
        "a": "The 15/42/13 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 13.8 kN / C0 6.65 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7302B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7302b",
      "7302B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7003-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7003",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 17,
    "D_mm": 35,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 7.95,
    "static_load_kN": 3.85,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.3,
    "limiting_speed_rpm": 21000,
    "max_rpm": 21000,
    "speed_oil_rpm": 28000,
    "weight_g": 46,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 17 x 35 x 10 mm, NTN 7003 sits in the standard-section 7000 single-row family of the angular-contact programme. Two fields make up the code — 70 is the single-row dimension series (standard-section 7000 single-row family) and 03 encodes the 17 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. NTN prints 7.95 kN dynamic and 3.85 kN static for this size and a 0.3 kN fatigue load limit Pu. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Heat-mounting to 80-90 deg C is the clean route onto a 17 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At 17 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "On a 17 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7003 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7003 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 7.95/3.85 kN ratings and 0.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7003; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7003?",
        "a": "7003 is a single-row angular contact ball bearing to ISO 15: 17 mm bore, 35 mm outside diameter, 10 mm width (0.669 x 1.378 x 0.394 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 7.95 kN, C0 3.85 kN and a 0.3 kN fatigue load limit Pu; the grease limiting speed is 21,000 r/min and the oil rating 28,000 r/min; mass about 46 g."
      },
      {
        "q": "How is the 7003 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 03 encodes the 17 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 35 mm OD and 10 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7003 support?",
        "a": "One 7003 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7003?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 21,000 r/min and the oil rating 28,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7003?",
        "a": "The 17/35/10 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 7.95 kN / C0 3.85 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7003",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7003",
      "7003-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5203S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5203S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 17,
    "D_mm": 40,
    "B_mm": 17.5,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 14.6,
    "static_load_kN": 9.05,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.54,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "speed_oil_rpm": 15000,
    "weight_g": 100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5203S appears as a medium-duty 5200S double-row family bearing of 17 mm bore, 40 mm outside diameter and 17.5 mm width. The designation breaks down as 52 is the double-row dimension series (medium-duty 5200S double-row family); 03 encodes the 17 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Against a deep-groove bearing of the same 17 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At 17 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "On a 17 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 11,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 14.6/9.05 kN ratings and 0.54 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5203S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5203S?",
        "a": "5203S is a double-row angular contact ball bearing to ISO 15: 17 mm bore, 40 mm outside diameter, 17.5 mm width (0.669 x 1.575 x 0.689 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 14.6 kN, C0 9.05 kN and a 0.54 kN fatigue load limit Pu; the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min; mass about 100 g."
      },
      {
        "q": "How is the 5203S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 03 encodes the 17 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 40 mm OD and 17.5 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5203S support?",
        "a": "5203S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5203S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5203S?",
        "a": "The 17/40/17.5 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 14.6 kN / C0 9.05 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5203S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5203s",
      "5203S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5203SCLLD",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5203SCLLD",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 17,
    "D_mm": 40,
    "B_mm": 17.5,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 12.7,
    "static_load_kN": 8.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.49,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "weight_g": 100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5203SCLLD appears as a medium-duty 5200S double-row family bearing of 17 mm bore, 40 mm outside diameter and 17.5 mm width. Two fields make up the code — 52 is the double-row dimension series (medium-duty 5200S double-row family) and 03 encodes the 17 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. A 17 mm shaft typically takes a j5/k5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At 17 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLD contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "A 5203SCLLD mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The C0 of 8.3 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 10,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 12.7/8.3 kN ratings and 0.49 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5203SCLLD; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5203SCLLD?",
        "a": "5203SCLLD is a sealed double-row angular contact ball bearing to ISO 15: 17 mm bore, 40 mm outside diameter, 17.5 mm width (0.669 x 1.575 x 0.689 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 12.7 kN, C0 8.3 kN and a 0.49 kN fatigue load limit Pu; the grease limiting speed is 10,000 r/min and no oil rating is printed for this execution; mass about 100 g."
      },
      {
        "q": "How is the 5203SCLLD designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 03 encodes the 17 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The 40 mm OD and 17.5 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5203SCLLD support?",
        "a": "5203SCLLD is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with contact rubber seals (grease-lubricated, no oil speed rating)."
      },
      {
        "q": "What lubrication speeds does NTN print for 5203SCLLD?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 10,000 r/min and no oil rating is printed for this execution. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5203SCLLD?",
        "a": "The 17/40/17.5 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 12.7 kN / C0 8.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5203SCLLD",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5203sclld",
      "5203SCLLD"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5203SCLLM",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5203SCLLM",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 17,
    "D_mm": 40,
    "B_mm": 17.5,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 12.7,
    "static_load_kN": 8.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.49,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "speed_oil_rpm": 15000,
    "weight_g": 100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 5200S double-row family entry 5203SCLLM carries a 17 mm bore in a 40 mm outside diameter, 17.5 mm wide envelope. Reading the code: 52 is the double-row dimension series (medium-duty 5200S double-row family), 03 encodes the 17 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. At roughly 11.5 mm of radial section, the catalogue still quotes 12.7 kN dynamic capacity for the 17 mm bore. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 17 mm bore give the working limits. ",
    "applications": [
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 17 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLM non-contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "The C0 of 8.3 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5203SCLLM without re-checking axial float, heat and housing width — the kinematics differ.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 12.7/8.3 kN ratings and 0.49 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5203SCLLM; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5203SCLLM?",
        "a": "5203SCLLM is a sealed double-row angular contact ball bearing to ISO 15: 17 mm bore, 40 mm outside diameter, 17.5 mm width (0.669 x 1.575 x 0.689 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 12.7 kN, C0 8.3 kN and a 0.49 kN fatigue load limit Pu; the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min; mass about 100 g."
      },
      {
        "q": "How is the 5203SCLLM designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 03 encodes the 17 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The 40 mm OD and 17.5 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5203SCLLM support?",
        "a": "5203SCLLM is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with non-contact rubber seals that keep the shield-level speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5203SCLLM?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5203SCLLM?",
        "a": "The 17/40/17.5 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 12.7 kN / C0 8.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5203SCLLM",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5203scllm",
      "5203SCLLM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5203SCZZ",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5203SCZZ",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 17,
    "D_mm": 40,
    "B_mm": 17.5,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 12.7,
    "static_load_kN": 8.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.49,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "speed_oil_rpm": 15000,
    "weight_g": 100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "5203SCZZ is an NTN sealed double-row angular contact ball bearing: medium-duty 5200S double-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 17 x 40 x 17.5 mm. The designation breaks down as 52 is the double-row dimension series (medium-duty 5200S double-row family); 03 encodes the 17 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. Catalogue mass is about 100 g, which at this 11.5 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At 17 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed ZZ shielded executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The C0 of 8.3 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 12.7/8.3 kN ratings and 0.49 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5203SCZZ; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5203SCZZ?",
        "a": "5203SCZZ is a sealed double-row angular contact ball bearing to ISO 15: 17 mm bore, 40 mm outside diameter, 17.5 mm width (0.669 x 1.575 x 0.689 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 12.7 kN, C0 8.3 kN and a 0.49 kN fatigue load limit Pu; the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min; mass about 100 g."
      },
      {
        "q": "How is the 5203SCZZ designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 03 encodes the 17 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The 40 mm OD and 17.5 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5203SCZZ support?",
        "a": "5203SCZZ is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with pressed-steel shields that keep the open-bearing speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5203SCZZ?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5203SCZZ?",
        "a": "The 17/40/17.5 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 12.7 kN / C0 8.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5203SCZZ",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5203sczz",
      "5203SCZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7203-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7203",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 17,
    "D_mm": 40,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 13.2,
    "static_load_kN": 6.6,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.52,
    "limiting_speed_rpm": 19000,
    "max_rpm": 19000,
    "speed_oil_rpm": 26000,
    "weight_g": 64,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 7200 single-row family, 7203 measures 17 mm across the bore, 40 mm over the outer ring and 12 mm across the faces. The designation breaks down as 72 is the single-row dimension series (medium-duty 7200 single-row family); 03 encodes the 17 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The static margin, C0 6.6 kN versus C 13.2 kN, is what supports slow oscillating duty and shock without immediate brinelling. Choose the medium-duty 7200 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Heat-mounting to 80-90 deg C is the clean route onto a 17 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At 17 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The C0 of 6.6 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Do not pair two random 7203 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 13.2/6.6 kN ratings and 0.52 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7203; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7203?",
        "a": "7203 is a single-row angular contact ball bearing to ISO 15: 17 mm bore, 40 mm outside diameter, 12 mm width (0.669 x 1.575 x 0.472 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 13.2 kN, C0 6.6 kN and a 0.52 kN fatigue load limit Pu; the grease limiting speed is 19,000 r/min and the oil rating 26,000 r/min; mass about 64 g."
      },
      {
        "q": "How is the 7203 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 03 encodes the 17 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 40 mm OD and 12 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7203 support?",
        "a": "One 7203 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7203?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 19,000 r/min and the oil rating 26,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7203?",
        "a": "The 17/40/12 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 13.2 kN / C0 6.6 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7203",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7203-ACCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7203-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7203-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7203-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7203-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7203-BEY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7203",
      "7203-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7203B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7203B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 17,
    "D_mm": 40,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 12.2,
    "static_load_kN": 6.1,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.48,
    "limiting_speed_rpm": 17000,
    "max_rpm": 17000,
    "speed_oil_rpm": 22000,
    "weight_g": 66,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7203B is the 17 mm bore member of NTN's medium-duty 7200 single-row family, with a 40 mm outside diameter and 12 mm section width. NTN builds the number from 72 is the single-row dimension series (medium-duty 7200 single-row family), then 03 encodes the 17 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Catalogue dynamic rating C is 12.2 kN against C0 6.1 kN — a C0/C ratio of 0.50 that is typical of an angular-contact contact ellipse. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. A 17 mm shaft typically takes a j5/k5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At 17 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Grease rated for deep-groove motor duty is not automatically right at 17,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The C0 of 6.1 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 12.2/6.1 kN ratings and 0.48 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7203B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7203B?",
        "a": "7203B is a single-row angular contact ball bearing to ISO 15: 17 mm bore, 40 mm outside diameter, 12 mm width (0.669 x 1.575 x 0.472 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 12.2 kN, C0 6.1 kN and a 0.48 kN fatigue load limit Pu; the grease limiting speed is 17,000 r/min and the oil rating 22,000 r/min; mass about 66 g."
      },
      {
        "q": "How is the 7203B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 03 encodes the 17 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 40 mm OD and 12 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7203B support?",
        "a": "One 7203B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7203B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 17,000 r/min and the oil rating 22,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7203B?",
        "a": "The 17/40/12 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 12.2 kN / C0 6.1 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7203B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7203b",
      "7203B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5303S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5303S",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 17,
    "D_mm": 47,
    "B_mm": 22.2,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 21,
    "static_load_kN": 12.6,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.77,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "speed_oil_rpm": 13000,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty 5300S double-row family, 5303S measures 17 mm across the bore, 47 mm over the outer ring and 22.2 mm across the faces. Decoding 5303S: 53 is the double-row dimension series (heavy-duty 5300S double-row family), with 03 encodes the 17 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. At roughly 15.0 mm of radial section, the catalogue still quotes 21 kN dynamic capacity for the 17 mm bore. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At 17 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5303S without re-checking axial float, heat and housing width — the kinematics differ.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 21/12.6 kN ratings and 0.77 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5303S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5303S?",
        "a": "5303S is a double-row angular contact ball bearing to ISO 15: 17 mm bore, 47 mm outside diameter, 22.2 mm width (0.669 x 1.85 x 0.874 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 21 kN, C0 12.6 kN and a 0.77 kN fatigue load limit Pu; the grease limiting speed is 10,000 r/min and the oil rating 13,000 r/min; mass about 180 g."
      },
      {
        "q": "How is the 5303S designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 03 encodes the 17 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 47 mm OD and 22.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5303S support?",
        "a": "5303S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5303S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 10,000 r/min and the oil rating 13,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5303S?",
        "a": "The 17/47/22.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 21 kN / C0 12.6 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5303S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5303s",
      "5303S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5303SCLLD",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5303SCLLD",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 17,
    "D_mm": 47,
    "B_mm": 22.2,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 19.6,
    "static_load_kN": 12.4,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.75,
    "limiting_speed_rpm": 9500,
    "max_rpm": 9500,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The heavy-duty 5300S double-row family entry 5303SCLLD carries a 17 mm bore in a 47 mm outside diameter, 22.2 mm wide envelope. NTN builds the number from 53 is the double-row dimension series (heavy-duty 5300S double-row family), then 03 encodes the 17 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. Catalogue mass is about 180 g, which at this 15.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Against a deep-groove bearing of the same 17 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Grease quantity matters as much as grade at 9,500 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At 17 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLD contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "The 9,500 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The C0 of 12.4 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 19.6/12.4 kN ratings and 0.75 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5303SCLLD; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5303SCLLD?",
        "a": "5303SCLLD is a sealed double-row angular contact ball bearing to ISO 15: 17 mm bore, 47 mm outside diameter, 22.2 mm width (0.669 x 1.85 x 0.874 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 19.6 kN, C0 12.4 kN and a 0.75 kN fatigue load limit Pu; the grease limiting speed is 9,500 r/min and no oil rating is printed for this execution; mass about 180 g."
      },
      {
        "q": "How is the 5303SCLLD designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 03 encodes the 17 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The 47 mm OD and 22.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5303SCLLD support?",
        "a": "5303SCLLD is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with contact rubber seals (grease-lubricated, no oil speed rating)."
      },
      {
        "q": "What lubrication speeds does NTN print for 5303SCLLD?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 9,500 r/min and no oil rating is printed for this execution. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5303SCLLD?",
        "a": "The 17/47/22.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 19.6 kN / C0 12.4 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5303SCLLD",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5303sclld",
      "5303SCLLD"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5303SCLLM",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5303SCLLM",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 17,
    "D_mm": 47,
    "B_mm": 22.2,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 19.6,
    "static_load_kN": 12.4,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.75,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "speed_oil_rpm": 13000,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "5303SCLLM is the 17 mm bore member of NTN's heavy-duty 5300S double-row family, with a 47 mm outside diameter and 22.2 mm section width. Decoding 5303SCLLM: 53 is the double-row dimension series (heavy-duty 5300S double-row family), with 03 encodes the 17 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. NTN prints 19.6 kN dynamic and 12.4 kN static for this size and a 0.75 kN fatigue load limit Pu. Against a deep-groove bearing of the same 17 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. A 17 mm shaft typically takes a j5/k5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At 17 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLM non-contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5303SCLLM without re-checking axial float, heat and housing width — the kinematics differ.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5303SCLLM without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 19.6/12.4 kN ratings and 0.75 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5303SCLLM; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5303SCLLM?",
        "a": "5303SCLLM is a sealed double-row angular contact ball bearing to ISO 15: 17 mm bore, 47 mm outside diameter, 22.2 mm width (0.669 x 1.85 x 0.874 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 19.6 kN, C0 12.4 kN and a 0.75 kN fatigue load limit Pu; the grease limiting speed is 10,000 r/min and the oil rating 13,000 r/min; mass about 180 g."
      },
      {
        "q": "How is the 5303SCLLM designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 03 encodes the 17 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The 47 mm OD and 22.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5303SCLLM support?",
        "a": "5303SCLLM is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with non-contact rubber seals that keep the shield-level speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5303SCLLM?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 10,000 r/min and the oil rating 13,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5303SCLLM?",
        "a": "The 17/47/22.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 19.6 kN / C0 12.4 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5303SCLLM",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5303scllm",
      "5303SCLLM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5303SCZZ",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5303SCZZ",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 17,
    "D_mm": 47,
    "B_mm": 22.2,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 19.6,
    "static_load_kN": 12.4,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.75,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "speed_oil_rpm": 13000,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5303SCZZ appears as a heavy-duty 5300S double-row family bearing of 17 mm bore, 47 mm outside diameter and 22.2 mm width. NTN builds the number from 53 is the double-row dimension series (heavy-duty 5300S double-row family), then 03 encodes the 17 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. NTN prints 19.6 kN dynamic and 12.4 kN static for this size and a 0.75 kN fatigue load limit Pu. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At 17 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed ZZ shielded executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5303SCZZ without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 19.6/12.4 kN ratings and 0.75 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5303SCZZ; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5303SCZZ?",
        "a": "5303SCZZ is a sealed double-row angular contact ball bearing to ISO 15: 17 mm bore, 47 mm outside diameter, 22.2 mm width (0.669 x 1.85 x 0.874 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 19.6 kN, C0 12.4 kN and a 0.75 kN fatigue load limit Pu; the grease limiting speed is 10,000 r/min and the oil rating 13,000 r/min; mass about 180 g."
      },
      {
        "q": "How is the 5303SCZZ designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 03 encodes the 17 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The 47 mm OD and 22.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5303SCZZ support?",
        "a": "5303SCZZ is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with pressed-steel shields that keep the open-bearing speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5303SCZZ?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 10,000 r/min and the oil rating 13,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5303SCZZ?",
        "a": "The 17/47/22.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 19.6 kN / C0 12.4 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5303SCZZ",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5303sczz",
      "5303SCZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7303-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7303",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 17,
    "D_mm": 47,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 17.7,
    "static_load_kN": 8.65,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.68,
    "limiting_speed_rpm": 18000,
    "max_rpm": 18000,
    "speed_oil_rpm": 24000,
    "weight_g": 107,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7303 is the 17 mm bore member of NTN's heavy-duty 7300 single-row family, with a 47 mm outside diameter and 14 mm section width. Reading the code: 73 is the single-row dimension series (heavy-duty 7300 single-row family), 03 encodes the 17 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. At roughly 15.0 mm of radial section, the catalogue still quotes 17.7 kN dynamic capacity for the 17 mm bore. For a 17 mm shaft with combined load, the practical shortlist is this series, its 7200-series lighter section, and — where thrust reverses — a back-to-back pair rather than a single row. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 17 mm bore give the working limits. ",
    "applications": [
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 17 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 17.7/8.65 kN ratings and 0.68 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7303; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7303?",
        "a": "7303 is a single-row angular contact ball bearing to ISO 15: 17 mm bore, 47 mm outside diameter, 14 mm width (0.669 x 1.85 x 0.551 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 17.7 kN, C0 8.65 kN and a 0.68 kN fatigue load limit Pu; the grease limiting speed is 18,000 r/min and the oil rating 24,000 r/min; mass about 107 g."
      },
      {
        "q": "How is the 7303 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 03 encodes the 17 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 47 mm OD and 14 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7303 support?",
        "a": "One 7303 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7303?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 18,000 r/min and the oil rating 24,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7303?",
        "a": "The 17/47/14 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 17.7 kN / C0 8.65 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7303",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7303-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7303-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7303-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7303",
      "7303-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7303B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7303B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 17,
    "D_mm": 47,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 16.4,
    "static_load_kN": 8.05,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.63,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "speed_oil_rpm": 20000,
    "weight_g": 109,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The heavy-duty 7300 single-row family entry 7303B carries a 17 mm bore in a 47 mm outside diameter, 14 mm wide envelope. Two fields make up the code — 73 is the single-row dimension series (heavy-duty 7300 single-row family) and 03 encodes the 17 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The static margin, C0 8.05 kN versus C 16.4 kN, is what supports slow oscillating duty and shock without immediate brinelling. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. A 17 mm shaft typically takes a j5/k5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At 17 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "The C0 of 8.05 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Do not pair two random 7303B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 16.4/8.05 kN ratings and 0.63 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7303B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7303B?",
        "a": "7303B is a single-row angular contact ball bearing to ISO 15: 17 mm bore, 47 mm outside diameter, 14 mm width (0.669 x 1.85 x 0.551 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 16.4 kN, C0 8.05 kN and a 0.63 kN fatigue load limit Pu; the grease limiting speed is 15,000 r/min and the oil rating 20,000 r/min; mass about 109 g."
      },
      {
        "q": "How is the 7303B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 03 encodes the 17 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 47 mm OD and 14 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7303B support?",
        "a": "One 7303B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7303B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 15,000 r/min and the oil rating 20,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7303B?",
        "a": "The 17/47/14 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 16.4 kN / C0 8.05 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7303B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7303b",
      "7303B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7004-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7004",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 20,
    "D_mm": 42,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 10.7,
    "static_load_kN": 5.6,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.44,
    "limiting_speed_rpm": 19000,
    "max_rpm": 19000,
    "speed_oil_rpm": 25000,
    "weight_g": 80,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7004 is the 20 mm bore member of NTN's standard-section 7000 single-row family, with a 42 mm outside diameter and 12 mm section width. NTN builds the number from 70 is the single-row dimension series (standard-section 7000 single-row family), then 04 encodes the 20 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Heat-mounting to 80-90 deg C is the clean route onto a 20 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At 20 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 19,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 10.7/5.6 kN ratings and 0.44 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7004; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7004?",
        "a": "7004 is a single-row angular contact ball bearing to ISO 15: 20 mm bore, 42 mm outside diameter, 12 mm width (0.787 x 1.654 x 0.472 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 10.7 kN, C0 5.6 kN and a 0.44 kN fatigue load limit Pu; the grease limiting speed is 19,000 r/min and the oil rating 25,000 r/min; mass about 80 g."
      },
      {
        "q": "How is the 7004 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 04 encodes the 20 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 42 mm OD and 12 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7004 support?",
        "a": "One 7004 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7004?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 19,000 r/min and the oil rating 25,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7004?",
        "a": "The 20/42/12 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 10.7 kN / C0 5.6 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7004",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7004",
      "7004-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5204S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5204S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 20,
    "D_mm": 47,
    "B_mm": 20.6,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 19.6,
    "static_load_kN": 12.4,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.75,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "speed_oil_rpm": 13000,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 20 x 47 x 20.6 mm, NTN 5204S sits in the medium-duty 5200S double-row family of the angular-contact programme. Two fields make up the code — 52 is the double-row dimension series (medium-duty 5200S double-row family) and 04 encodes the 20 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The radial section height here is 13.5 mm, and the catalogue couples that with C 19.6 kN / C0 12.4 kN. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. A 20 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At 20 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "A 5204S mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The C0 of 12.4 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 19.6/12.4 kN ratings and 0.75 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5204S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5204S?",
        "a": "5204S is a double-row angular contact ball bearing to ISO 15: 20 mm bore, 47 mm outside diameter, 20.6 mm width (0.787 x 1.85 x 0.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 19.6 kN, C0 12.4 kN and a 0.75 kN fatigue load limit Pu; the grease limiting speed is 10,000 r/min and the oil rating 13,000 r/min; mass about 160 g."
      },
      {
        "q": "How is the 5204S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 04 encodes the 20 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 47 mm OD and 20.6 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5204S support?",
        "a": "5204S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5204S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 10,000 r/min and the oil rating 13,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5204S?",
        "a": "The 20/47/20.6 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 19.6 kN / C0 12.4 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5204S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5204s",
      "5204S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5204SCLLD",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5204SCLLD",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 20,
    "D_mm": 47,
    "B_mm": 20.6,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 15.9,
    "static_load_kN": 10.7,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.64,
    "limiting_speed_rpm": 9000,
    "max_rpm": 9000,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5204SCLLD appears as a medium-duty 5200S double-row family bearing of 20 mm bore, 47 mm outside diameter and 20.6 mm width. Reading the code: 52 is the double-row dimension series (medium-duty 5200S double-row family), 04 encodes the 20 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The static margin, C0 10.7 kN versus C 15.9 kN, is what supports slow oscillating duty and shock without immediate brinelling. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 20 mm bore give the working limits. ",
    "applications": [
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 20 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLD contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "The 9,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 9,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Do not pair two random 5204SCLLD bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 15.9/10.7 kN ratings and 0.64 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5204SCLLD; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5204SCLLD?",
        "a": "5204SCLLD is a sealed double-row angular contact ball bearing to ISO 15: 20 mm bore, 47 mm outside diameter, 20.6 mm width (0.787 x 1.85 x 0.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 15.9 kN, C0 10.7 kN and a 0.64 kN fatigue load limit Pu; the grease limiting speed is 9,000 r/min and no oil rating is printed for this execution; mass about 160 g."
      },
      {
        "q": "How is the 5204SCLLD designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 04 encodes the 20 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The 47 mm OD and 20.6 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5204SCLLD support?",
        "a": "5204SCLLD is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with contact rubber seals (grease-lubricated, no oil speed rating)."
      },
      {
        "q": "What lubrication speeds does NTN print for 5204SCLLD?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 9,000 r/min and no oil rating is printed for this execution. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5204SCLLD?",
        "a": "The 20/47/20.6 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 15.9 kN / C0 10.7 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5204SCLLD",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5204sclld",
      "5204SCLLD"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5204SCLLM",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5204SCLLM",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 20,
    "D_mm": 47,
    "B_mm": 20.6,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 15.9,
    "static_load_kN": 10.7,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.64,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "speed_oil_rpm": 13000,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 5200S double-row family entry 5204SCLLM carries a 20 mm bore in a 47 mm outside diameter, 20.6 mm wide envelope. The designation breaks down as 52 is the double-row dimension series (medium-duty 5200S double-row family); 04 encodes the 20 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. On speed, the grease limiting speed is 10,000 r/min and the oil rating 13,000 r/min. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At 20 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLM non-contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Do not pair two random 5204SCLLM bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The C0 of 10.7 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 15.9/10.7 kN ratings and 0.64 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5204SCLLM; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5204SCLLM?",
        "a": "5204SCLLM is a sealed double-row angular contact ball bearing to ISO 15: 20 mm bore, 47 mm outside diameter, 20.6 mm width (0.787 x 1.85 x 0.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 15.9 kN, C0 10.7 kN and a 0.64 kN fatigue load limit Pu; the grease limiting speed is 10,000 r/min and the oil rating 13,000 r/min; mass about 160 g."
      },
      {
        "q": "How is the 5204SCLLM designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 04 encodes the 20 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The 47 mm OD and 20.6 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5204SCLLM support?",
        "a": "5204SCLLM is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with non-contact rubber seals that keep the shield-level speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5204SCLLM?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 10,000 r/min and the oil rating 13,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5204SCLLM?",
        "a": "The 20/47/20.6 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 15.9 kN / C0 10.7 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5204SCLLM",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5204scllm",
      "5204SCLLM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5204SCZZ",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5204SCZZ",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 20,
    "D_mm": 47,
    "B_mm": 20.6,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 15.9,
    "static_load_kN": 10.7,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.64,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "speed_oil_rpm": 13000,
    "weight_g": 160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5204SCZZ appears as a medium-duty 5200S double-row family bearing of 20 mm bore, 47 mm outside diameter and 20.6 mm width. Two fields make up the code — 52 is the double-row dimension series (medium-duty 5200S double-row family) and 04 encodes the 20 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The radial section height here is 13.5 mm, and the catalogue couples that with C 15.9 kN / C0 10.7 kN. Against a deep-groove bearing of the same 20 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At 20 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed ZZ shielded executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "The C0 of 10.7 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 15.9/10.7 kN ratings and 0.64 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5204SCZZ; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5204SCZZ?",
        "a": "5204SCZZ is a sealed double-row angular contact ball bearing to ISO 15: 20 mm bore, 47 mm outside diameter, 20.6 mm width (0.787 x 1.85 x 0.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 15.9 kN, C0 10.7 kN and a 0.64 kN fatigue load limit Pu; the grease limiting speed is 10,000 r/min and the oil rating 13,000 r/min; mass about 160 g."
      },
      {
        "q": "How is the 5204SCZZ designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 04 encodes the 20 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The 47 mm OD and 20.6 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5204SCZZ support?",
        "a": "5204SCZZ is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with pressed-steel shields that keep the open-bearing speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5204SCZZ?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 10,000 r/min and the oil rating 13,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5204SCZZ?",
        "a": "The 20/47/20.6 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 15.9 kN / C0 10.7 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5204SCZZ",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5204sczz",
      "5204SCZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7204-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7204",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 20,
    "D_mm": 47,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 16.1,
    "static_load_kN": 8.4,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.66,
    "limiting_speed_rpm": 17000,
    "max_rpm": 17000,
    "speed_oil_rpm": 23000,
    "weight_g": 100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7204 is the 20 mm bore member of NTN's medium-duty 7200 single-row family, with a 47 mm outside diameter and 14 mm section width. NTN builds the number from 72 is the single-row dimension series (medium-duty 7200 single-row family), then 04 encodes the 20 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue dynamic rating C is 16.1 kN against C0 8.4 kN — a C0/C ratio of 0.52 that is typical of an angular-contact contact ellipse. Against a deep-groove bearing of the same 20 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Grease quantity matters as much as grade at 17,000 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At 20 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "On a 20 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 16.1/8.4 kN ratings and 0.66 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7204; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7204?",
        "a": "7204 is a single-row angular contact ball bearing to ISO 15: 20 mm bore, 47 mm outside diameter, 14 mm width (0.787 x 1.85 x 0.551 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 16.1 kN, C0 8.4 kN and a 0.66 kN fatigue load limit Pu; the grease limiting speed is 17,000 r/min and the oil rating 23,000 r/min; mass about 100 g."
      },
      {
        "q": "How is the 7204 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 04 encodes the 20 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 47 mm OD and 14 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7204 support?",
        "a": "One 7204 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7204?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 17,000 r/min and the oil rating 23,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7204?",
        "a": "The 20/47/14 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 16.1 kN / C0 8.4 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7204",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7204-ACCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7204-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7204-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7204-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7204-BECBPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7204-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7204-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7204",
      "7204-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7204B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7204B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 20,
    "D_mm": 47,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 14.7,
    "static_load_kN": 7.7,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.6,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "speed_oil_rpm": 20000,
    "weight_g": 102,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7204B appears as a medium-duty 7200 single-row family bearing of 20 mm bore, 47 mm outside diameter and 14 mm width. Reading the code: 72 is the single-row dimension series (medium-duty 7200 single-row family), 04 encodes the 20 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). NTN prints 14.7 kN dynamic and 7.7 kN static for this size and a 0.6 kN fatigue load limit Pu. Choose the medium-duty 7200 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 20 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "On a 20 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Grease rated for deep-groove motor duty is not automatically right at 15,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7204B without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 14.7/7.7 kN ratings and 0.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7204B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7204B?",
        "a": "7204B is a single-row angular contact ball bearing to ISO 15: 20 mm bore, 47 mm outside diameter, 14 mm width (0.787 x 1.85 x 0.551 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 14.7 kN, C0 7.7 kN and a 0.6 kN fatigue load limit Pu; the grease limiting speed is 15,000 r/min and the oil rating 20,000 r/min; mass about 102 g."
      },
      {
        "q": "How is the 7204B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 04 encodes the 20 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 47 mm OD and 14 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7204B support?",
        "a": "One 7204B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7204B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 15,000 r/min and the oil rating 20,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7204B?",
        "a": "The 20/47/14 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 14.7 kN / C0 7.7 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7204B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7204b",
      "7204B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5304S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5304S",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 20,
    "D_mm": 52,
    "B_mm": 22.2,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 24.6,
    "static_load_kN": 15,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.93,
    "limiting_speed_rpm": 9000,
    "max_rpm": 9000,
    "speed_oil_rpm": 12000,
    "weight_g": 220,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 5304S belongs to the heavy-duty 5300S double-row family: the catalogue boundary dimensions read 20 / 52 / 22.2 mm (bore / OD / width). The designation breaks down as 53 is the double-row dimension series (heavy-duty 5300S double-row family); 04 encodes the 20 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. A 20 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At 20 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "The 9,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 9,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 24.6/15 kN ratings and 0.93 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5304S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5304S?",
        "a": "5304S is a double-row angular contact ball bearing to ISO 15: 20 mm bore, 52 mm outside diameter, 22.2 mm width (0.787 x 2.047 x 0.874 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 24.6 kN, C0 15 kN and a 0.93 kN fatigue load limit Pu; the grease limiting speed is 9,000 r/min and the oil rating 12,000 r/min; mass about 220 g."
      },
      {
        "q": "How is the 5304S designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 04 encodes the 20 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 52 mm OD and 22.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5304S support?",
        "a": "5304S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5304S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 9,000 r/min and the oil rating 12,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5304S?",
        "a": "The 20/52/22.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 24.6 kN / C0 15 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5304S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5304s",
      "5304S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7304-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7304",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 20,
    "D_mm": 52,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 20.7,
    "static_load_kN": 10.4,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.81,
    "limiting_speed_rpm": 16000,
    "max_rpm": 16000,
    "speed_oil_rpm": 21000,
    "weight_g": 138,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty 7300 single-row family, 7304 measures 20 mm across the bore, 52 mm over the outer ring and 15 mm across the faces. Decoding 7304: 73 is the single-row dimension series (heavy-duty 7300 single-row family), with 04 encodes the 20 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. NTN prints 20.7 kN dynamic and 10.4 kN static for this size and a 0.81 kN fatigue load limit Pu. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 20 mm bore give the working limits. ",
    "applications": [
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At 20 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Grease rated for deep-groove motor duty is not automatically right at 16,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7304 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 20.7/10.4 kN ratings and 0.81 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7304; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7304?",
        "a": "7304 is a single-row angular contact ball bearing to ISO 15: 20 mm bore, 52 mm outside diameter, 15 mm width (0.787 x 2.047 x 0.591 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 20.7 kN, C0 10.4 kN and a 0.81 kN fatigue load limit Pu; the grease limiting speed is 16,000 r/min and the oil rating 21,000 r/min; mass about 138 g."
      },
      {
        "q": "How is the 7304 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 04 encodes the 20 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 52 mm OD and 15 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7304 support?",
        "a": "One 7304 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7304?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 16,000 r/min and the oil rating 21,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7304?",
        "a": "The 20/52/15 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 20.7 kN / C0 10.4 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7304",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7304-ACCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7304-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7304-BECBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7304-BECBP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7304-BECBPH",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7304-BECBY",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7304-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7304",
      "7304-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7304B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7304B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 20,
    "D_mm": 52,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 19.2,
    "static_load_kN": 9.65,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.76,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "speed_oil_rpm": 18000,
    "weight_g": 141,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty 7300 single-row family, 7304B measures 20 mm across the bore, 52 mm over the outer ring and 15 mm across the faces. NTN builds the number from 73 is the single-row dimension series (heavy-duty 7300 single-row family), then 04 encodes the 20 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Catalogue dynamic rating C is 19.2 kN against C0 9.65 kN — a C0/C ratio of 0.50 that is typical of an angular-contact contact ellipse. For a 20 mm shaft with combined load, the practical shortlist is this series, its 7200-series lighter section, and — where thrust reverses — a back-to-back pair rather than a single row. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At 20 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "On a 20 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 19.2/9.65 kN ratings and 0.76 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7304B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7304B?",
        "a": "7304B is a single-row angular contact ball bearing to ISO 15: 20 mm bore, 52 mm outside diameter, 15 mm width (0.787 x 2.047 x 0.591 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 19.2 kN, C0 9.65 kN and a 0.76 kN fatigue load limit Pu; the grease limiting speed is 13,000 r/min and the oil rating 18,000 r/min; mass about 141 g."
      },
      {
        "q": "How is the 7304B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 04 encodes the 20 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 52 mm OD and 15 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7304B support?",
        "a": "One 7304B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7304B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 13,000 r/min and the oil rating 18,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7304B?",
        "a": "The 20/52/15 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 19.2 kN / C0 9.65 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7304B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7304b",
      "7304B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7905",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7905",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 25,
    "D_mm": 42,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 7.9,
    "static_load_kN": 4.95,
    "cage_type": "polymer_PA66",
    "fatigue_load_limit_kN": 0.36,
    "limiting_speed_rpm": 17000,
    "max_rpm": 17000,
    "speed_oil_rpm": 22000,
    "weight_g": 50,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 25 x 42 x 9 mm, NTN 7905 sits in the extra-light, high-speed 7900 single-row family of the angular-contact programme. Reading the code: 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), 05 encodes the 25 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 30 deg contact angle is the lever that turns the 4.95 kN static rating into useful one-direction thrust capacity. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Grease quantity matters as much as grade at 17,000 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 25 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 4.95 kN really covers the worst static case before substituting it for a 7000.",
      "On a 25 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "A 7905 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 7.9/4.95 kN ratings and 0.36 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7905; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7905?",
        "a": "7905 is a single-row angular contact ball bearing to ISO 15: 25 mm bore, 42 mm outside diameter, 9 mm width (0.984 x 1.654 x 0.354 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 7.9 kN, C0 4.95 kN and a 0.36 kN fatigue load limit Pu; the grease limiting speed is 17,000 r/min and the oil rating 22,000 r/min; mass about 50 g."
      },
      {
        "q": "How is the 7905 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 05 encodes the 25 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 42 mm OD and 9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7905 support?",
        "a": "One 7905 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7905?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 17,000 r/min and the oil rating 22,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7905?",
        "a": "The 25/42/9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 7.9 kN / C0 4.95 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7905",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7905"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7005-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7005",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 25,
    "D_mm": 47,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 11.9,
    "static_load_kN": 6.85,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.54,
    "limiting_speed_rpm": 16000,
    "max_rpm": 16000,
    "speed_oil_rpm": 21000,
    "weight_g": 93,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 25 x 47 x 12 mm, NTN 7005 sits in the standard-section 7000 single-row family of the angular-contact programme. Decoding 7005: 70 is the single-row dimension series (standard-section 7000 single-row family), with 05 encodes the 25 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The radial section height here is 11.0 mm, and the catalogue couples that with C 11.9 kN / C0 6.85 kN. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Grease quantity matters as much as grade at 16,000 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At 25 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The C0 of 6.85 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Do not pair two random 7005 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 11.9/6.85 kN ratings and 0.54 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7005; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7005?",
        "a": "7005 is a single-row angular contact ball bearing to ISO 15: 25 mm bore, 47 mm outside diameter, 12 mm width (0.984 x 1.85 x 0.472 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 11.9 kN, C0 6.85 kN and a 0.54 kN fatigue load limit Pu; the grease limiting speed is 16,000 r/min and the oil rating 21,000 r/min; mass about 93 g."
      },
      {
        "q": "How is the 7005 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 05 encodes the 25 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 47 mm OD and 12 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7005 support?",
        "a": "One 7005 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7005?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 16,000 r/min and the oil rating 21,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7005?",
        "a": "The 25/47/12 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 11.9 kN / C0 6.85 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7005",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7005",
      "7005-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5205S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5205S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 25,
    "D_mm": 52,
    "B_mm": 20.6,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 21.3,
    "static_load_kN": 14.7,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.88,
    "limiting_speed_rpm": 8500,
    "max_rpm": 8500,
    "speed_oil_rpm": 11000,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "5205S is an NTN double-row angular contact ball bearing: medium-duty 5200S double-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 25 x 52 x 20.6 mm. NTN builds the number from 52 is the double-row dimension series (medium-duty 5200S double-row family), then 05 encodes the 25 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. On speed, the grease limiting speed is 8,500 r/min and the oil rating 11,000 r/min. For a 25 mm shaft with combined load, the practical shortlist is this series, its neighbouring dimension series, and — where thrust reverses — a back-to-back pair rather than a single row. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At 25 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Grease rated for deep-groove motor duty is not automatically right at 8,500 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The C0 of 14.7 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 21.3/14.7 kN ratings and 0.88 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5205S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5205S?",
        "a": "5205S is a double-row angular contact ball bearing to ISO 15: 25 mm bore, 52 mm outside diameter, 20.6 mm width (0.984 x 2.047 x 0.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 21.3 kN, C0 14.7 kN and a 0.88 kN fatigue load limit Pu; the grease limiting speed is 8,500 r/min and the oil rating 11,000 r/min; mass about 180 g."
      },
      {
        "q": "How is the 5205S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 05 encodes the 25 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 52 mm OD and 20.6 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5205S support?",
        "a": "5205S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5205S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 8,500 r/min and the oil rating 11,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5205S?",
        "a": "The 25/52/20.6 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 21.3 kN / C0 14.7 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5205S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5205s",
      "5205S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5205SCLLD",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5205SCLLD",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 25,
    "D_mm": 52,
    "B_mm": 20.6,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 16.9,
    "static_load_kN": 12.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.74,
    "limiting_speed_rpm": 7500,
    "max_rpm": 7500,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 5200S double-row family, 5205SCLLD measures 25 mm across the bore, 52 mm over the outer ring and 20.6 mm across the faces. Two fields make up the code — 52 is the double-row dimension series (medium-duty 5200S double-row family) and 05 encodes the 25 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. At roughly 13.5 mm of radial section, the catalogue still quotes 16.9 kN dynamic capacity for the 25 mm bore. For a 25 mm shaft with combined load, the practical shortlist is this series, its neighbouring dimension series, and — where thrust reverses — a back-to-back pair rather than a single row. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 25 mm bore give the working limits. ",
    "applications": [
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At 25 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLD contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "The C0 of 12.3 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5205SCLLD without re-checking axial float, heat and housing width — the kinematics differ.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 16.9/12.3 kN ratings and 0.74 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5205SCLLD; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5205SCLLD?",
        "a": "5205SCLLD is a sealed double-row angular contact ball bearing to ISO 15: 25 mm bore, 52 mm outside diameter, 20.6 mm width (0.984 x 2.047 x 0.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 16.9 kN, C0 12.3 kN and a 0.74 kN fatigue load limit Pu; the grease limiting speed is 7,500 r/min and no oil rating is printed for this execution; mass about 180 g."
      },
      {
        "q": "How is the 5205SCLLD designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 05 encodes the 25 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The 52 mm OD and 20.6 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5205SCLLD support?",
        "a": "5205SCLLD is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with contact rubber seals (grease-lubricated, no oil speed rating)."
      },
      {
        "q": "What lubrication speeds does NTN print for 5205SCLLD?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,500 r/min and no oil rating is printed for this execution. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5205SCLLD?",
        "a": "The 25/52/20.6 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 16.9 kN / C0 12.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5205SCLLD",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5205sclld",
      "5205SCLLD"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5205SCLLM",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5205SCLLM",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 25,
    "D_mm": 52,
    "B_mm": 20.6,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 16.9,
    "static_load_kN": 12.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.74,
    "limiting_speed_rpm": 8500,
    "max_rpm": 8500,
    "speed_oil_rpm": 11000,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5205SCLLM appears as a medium-duty 5200S double-row family bearing of 25 mm bore, 52 mm outside diameter and 20.6 mm width. Reading the code: 52 is the double-row dimension series (medium-duty 5200S double-row family), 05 encodes the 25 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The oil rating of 11,000 r/min sits 2,500 r/min above the 8,500 r/min grease figure — a 1.29x step that says how much headroom oil cooling buys. For a 25 mm shaft with combined load, the practical shortlist is this series, its neighbouring dimension series, and — where thrust reverses — a back-to-back pair rather than a single row. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 25 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLM non-contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "On a 25 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "On a 25 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Grease rated for deep-groove motor duty is not automatically right at 8,500 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 16.9/12.3 kN ratings and 0.74 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5205SCLLM; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5205SCLLM?",
        "a": "5205SCLLM is a sealed double-row angular contact ball bearing to ISO 15: 25 mm bore, 52 mm outside diameter, 20.6 mm width (0.984 x 2.047 x 0.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 16.9 kN, C0 12.3 kN and a 0.74 kN fatigue load limit Pu; the grease limiting speed is 8,500 r/min and the oil rating 11,000 r/min; mass about 180 g."
      },
      {
        "q": "How is the 5205SCLLM designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 05 encodes the 25 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The 52 mm OD and 20.6 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5205SCLLM support?",
        "a": "5205SCLLM is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with non-contact rubber seals that keep the shield-level speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5205SCLLM?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 8,500 r/min and the oil rating 11,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5205SCLLM?",
        "a": "The 25/52/20.6 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 16.9 kN / C0 12.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5205SCLLM",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5205scllm",
      "5205SCLLM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5205SCZZ",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5205SCZZ",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 25,
    "D_mm": 52,
    "B_mm": 20.6,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 16.9,
    "static_load_kN": 12.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.74,
    "limiting_speed_rpm": 8500,
    "max_rpm": 8500,
    "speed_oil_rpm": 11000,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "5205SCZZ is an NTN sealed double-row angular contact ball bearing: medium-duty 5200S double-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 25 x 52 x 20.6 mm. Reading the code: 52 is the double-row dimension series (medium-duty 5200S double-row family), 05 encodes the 25 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. On speed, the grease limiting speed is 8,500 r/min and the oil rating 11,000 r/min. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 25 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed ZZ shielded executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "Grease rated for deep-groove motor duty is not automatically right at 8,500 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 8,500 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The C0 of 12.3 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 16.9/12.3 kN ratings and 0.74 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5205SCZZ; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5205SCZZ?",
        "a": "5205SCZZ is a sealed double-row angular contact ball bearing to ISO 15: 25 mm bore, 52 mm outside diameter, 20.6 mm width (0.984 x 2.047 x 0.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 16.9 kN, C0 12.3 kN and a 0.74 kN fatigue load limit Pu; the grease limiting speed is 8,500 r/min and the oil rating 11,000 r/min; mass about 180 g."
      },
      {
        "q": "How is the 5205SCZZ designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 05 encodes the 25 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The 52 mm OD and 20.6 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5205SCZZ support?",
        "a": "5205SCZZ is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with pressed-steel shields that keep the open-bearing speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5205SCZZ?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 8,500 r/min and the oil rating 11,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5205SCZZ?",
        "a": "The 25/52/20.6 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 16.9 kN / C0 12.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5205SCZZ",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5205sczz",
      "5205SCZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7205-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7205",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 25,
    "D_mm": 52,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 18,
    "static_load_kN": 10.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.81,
    "limiting_speed_rpm": 14000,
    "max_rpm": 14000,
    "speed_oil_rpm": 19000,
    "weight_g": 125,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 7200 single-row family, 7205 measures 25 mm across the bore, 52 mm over the outer ring and 15 mm across the faces. Reading the code: 72 is the single-row dimension series (medium-duty 7200 single-row family), 05 encodes the 25 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. At roughly 13.5 mm of radial section, the catalogue still quotes 18 kN dynamic capacity for the 25 mm bore. Choose the medium-duty 7200 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Grease quantity matters as much as grade at 14,000 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 25 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 14,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 18/10.3 kN ratings and 0.81 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7205; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7205?",
        "a": "7205 is a single-row angular contact ball bearing to ISO 15: 25 mm bore, 52 mm outside diameter, 15 mm width (0.984 x 2.047 x 0.591 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 18 kN, C0 10.3 kN and a 0.81 kN fatigue load limit Pu; the grease limiting speed is 14,000 r/min and the oil rating 19,000 r/min; mass about 125 g."
      },
      {
        "q": "How is the 7205 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 05 encodes the 25 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 52 mm OD and 15 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7205 support?",
        "a": "One 7205 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7205?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 14,000 r/min and the oil rating 19,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7205?",
        "a": "The 25/52/15 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 18 kN / C0 10.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7205",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7205-ACCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7205-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7205-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7205-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7205-BECBPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7205-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7205-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7205-BEY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7205",
      "7205-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7205B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7205B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 25,
    "D_mm": 52,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 16.4,
    "static_load_kN": 9.4,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.74,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "speed_oil_rpm": 16000,
    "weight_g": 129,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 25 x 52 x 15 mm, NTN 7205B sits in the medium-duty 7200 single-row family of the angular-contact programme. Decoding 7205B: 72 is the single-row dimension series (medium-duty 7200 single-row family), with 05 encodes the 25 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Catalogue mass is about 129 g, which at this 13.5 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Against a deep-groove bearing of the same 25 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Grease quantity matters as much as grade at 12,000 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At 25 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "A 7205B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7205B without re-checking axial float, heat and housing width — the kinematics differ.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 16.4/9.4 kN ratings and 0.74 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7205B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7205B?",
        "a": "7205B is a single-row angular contact ball bearing to ISO 15: 25 mm bore, 52 mm outside diameter, 15 mm width (0.984 x 2.047 x 0.591 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 16.4 kN, C0 9.4 kN and a 0.74 kN fatigue load limit Pu; the grease limiting speed is 12,000 r/min and the oil rating 16,000 r/min; mass about 129 g."
      },
      {
        "q": "How is the 7205B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 05 encodes the 25 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 52 mm OD and 15 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7205B support?",
        "a": "One 7205B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7205B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 12,000 r/min and the oil rating 16,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7205B?",
        "a": "The 25/52/15 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 16.4 kN / C0 9.4 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7205B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7205b",
      "7205B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5305S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5305S",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 25,
    "D_mm": 62,
    "B_mm": 25.4,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 32.5,
    "static_load_kN": 20.7,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.3,
    "limiting_speed_rpm": 7500,
    "max_rpm": 7500,
    "speed_oil_rpm": 10000,
    "weight_g": 350,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "5305S is the 25 mm bore member of NTN's heavy-duty 5300S double-row family, with a 62 mm outside diameter and 25.4 mm section width. Two fields make up the code — 53 is the double-row dimension series (heavy-duty 5300S double-row family) and 05 encodes the 25 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The radial section height here is 18.5 mm, and the catalogue couples that with C 32.5 kN / C0 20.7 kN. The 25/62/25.4 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At 25 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "On a 25 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 32.5/20.7 kN ratings and 1.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5305S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5305S?",
        "a": "5305S is a double-row angular contact ball bearing to ISO 15: 25 mm bore, 62 mm outside diameter, 25.4 mm width (0.984 x 2.441 x 1 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 32.5 kN, C0 20.7 kN and a 1.3 kN fatigue load limit Pu; the grease limiting speed is 7,500 r/min and the oil rating 10,000 r/min; mass about 350 g."
      },
      {
        "q": "How is the 5305S designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 05 encodes the 25 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 62 mm OD and 25.4 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5305S support?",
        "a": "5305S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5305S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,500 r/min and the oil rating 10,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5305S?",
        "a": "The 25/62/25.4 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 32.5 kN / C0 20.7 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5305S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5305s",
      "5305S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5305SCLLD",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5305SCLLD",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 25,
    "D_mm": 62,
    "B_mm": 25.4,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 25.2,
    "static_load_kN": 18.2,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.1,
    "limiting_speed_rpm": 6300,
    "max_rpm": 6300,
    "weight_g": 360,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5305SCLLD appears as a heavy-duty 5300S double-row family bearing of 25 mm bore, 62 mm outside diameter and 25.4 mm width. NTN builds the number from 53 is the double-row dimension series (heavy-duty 5300S double-row family), then 05 encodes the 25 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. NTN prints 25.2 kN dynamic and 18.2 kN static for this size and a 1.1 kN fatigue load limit Pu. Choose the heavy-duty 5300S double-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. A 25 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At 25 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLD contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5305SCLLD without re-checking axial float, heat and housing width — the kinematics differ.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5305SCLLD without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 25.2/18.2 kN ratings and 1.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5305SCLLD; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5305SCLLD?",
        "a": "5305SCLLD is a sealed double-row angular contact ball bearing to ISO 15: 25 mm bore, 62 mm outside diameter, 25.4 mm width (0.984 x 2.441 x 1 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 25.2 kN, C0 18.2 kN and a 1.1 kN fatigue load limit Pu; the grease limiting speed is 6,300 r/min and no oil rating is printed for this execution; mass about 360 g."
      },
      {
        "q": "How is the 5305SCLLD designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 05 encodes the 25 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The 62 mm OD and 25.4 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5305SCLLD support?",
        "a": "5305SCLLD is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with contact rubber seals (grease-lubricated, no oil speed rating)."
      },
      {
        "q": "What lubrication speeds does NTN print for 5305SCLLD?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,300 r/min and no oil rating is printed for this execution. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5305SCLLD?",
        "a": "The 25/62/25.4 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 25.2 kN / C0 18.2 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5305SCLLD",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5305sclld",
      "5305SCLLD"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5305SCLLM",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5305SCLLM",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 25,
    "D_mm": 62,
    "B_mm": 25.4,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 25.2,
    "static_load_kN": 18.2,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.1,
    "limiting_speed_rpm": 7500,
    "max_rpm": 7500,
    "speed_oil_rpm": 10000,
    "weight_g": 360,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The heavy-duty 5300S double-row family entry 5305SCLLM carries a 25 mm bore in a 62 mm outside diameter, 25.4 mm wide envelope. Decoding 5305SCLLM: 53 is the double-row dimension series (heavy-duty 5300S double-row family), with 05 encodes the 25 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. Catalogue dynamic rating C is 25.2 kN against C0 18.2 kN — a C0/C ratio of 0.72 that is typical of an angular-contact contact ellipse. Choose the heavy-duty 5300S double-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 25 mm bore give the working limits. ",
    "applications": [
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At 25 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed LLM non-contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "On a 25 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 25.2/18.2 kN ratings and 1.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5305SCLLM; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5305SCLLM?",
        "a": "5305SCLLM is a sealed double-row angular contact ball bearing to ISO 15: 25 mm bore, 62 mm outside diameter, 25.4 mm width (0.984 x 2.441 x 1 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 25.2 kN, C0 18.2 kN and a 1.1 kN fatigue load limit Pu; the grease limiting speed is 7,500 r/min and the oil rating 10,000 r/min; mass about 360 g."
      },
      {
        "q": "How is the 5305SCLLM designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 05 encodes the 25 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The 62 mm OD and 25.4 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5305SCLLM support?",
        "a": "5305SCLLM is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with non-contact rubber seals that keep the shield-level speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5305SCLLM?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,500 r/min and the oil rating 10,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5305SCLLM?",
        "a": "The 25/62/25.4 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 25.2 kN / C0 18.2 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5305SCLLM",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5305scllm",
      "5305SCLLM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5305SCZZ",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5305SCZZ",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 25,
    "D_mm": 62,
    "B_mm": 25.4,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 25.2,
    "static_load_kN": 18.2,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.1,
    "limiting_speed_rpm": 7500,
    "max_rpm": 7500,
    "speed_oil_rpm": 10000,
    "weight_g": 360,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5305SCZZ appears as a heavy-duty 5300S double-row family bearing of 25 mm bore, 62 mm outside diameter and 25.4 mm width. The designation breaks down as 53 is the double-row dimension series (heavy-duty 5300S double-row family); 05 encodes the 25 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The radial section height here is 18.5 mm, and the catalogue couples that with C 25.2 kN / C0 18.2 kN. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "precision instrument and encoder support shafts",
      "small machine-tool spindle and live-centre positions",
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At 25 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "Sealed ZZ shielded executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "The 7,500 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 25.2/18.2 kN ratings and 1.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5305SCZZ; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5305SCZZ?",
        "a": "5305SCZZ is a sealed double-row angular contact ball bearing to ISO 15: 25 mm bore, 62 mm outside diameter, 25.4 mm width (0.984 x 2.441 x 1 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 25.2 kN, C0 18.2 kN and a 1.1 kN fatigue load limit Pu; the grease limiting speed is 7,500 r/min and the oil rating 10,000 r/min; mass about 360 g."
      },
      {
        "q": "How is the 5305SCZZ designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 05 encodes the 25 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The 62 mm OD and 25.4 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5305SCZZ support?",
        "a": "5305SCZZ is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with pressed-steel shields that keep the open-bearing speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5305SCZZ?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,500 r/min and the oil rating 10,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5305SCZZ?",
        "a": "The 25/62/25.4 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 25.2 kN / C0 18.2 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5305SCZZ",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5305sczz",
      "5305SCZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7305-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7305",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 25,
    "D_mm": 62,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 29.3,
    "static_load_kN": 15.8,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.24,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "speed_oil_rpm": 17000,
    "weight_g": 230,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7305 is the 25 mm bore member of NTN's heavy-duty 7300 single-row family, with a 62 mm outside diameter and 17 mm section width. The designation breaks down as 73 is the single-row dimension series (heavy-duty 7300 single-row family); 05 encodes the 25 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue mass is about 230 g, which at this 18.5 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Against a deep-groove bearing of the same 25 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions",
      "small gearbox pinion shafts with helical gears",
      "precision instrument and encoder support shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At 25 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "On a 25 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "On a 25 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 29.3/15.8 kN ratings and 1.24 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7305; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7305?",
        "a": "7305 is a single-row angular contact ball bearing to ISO 15: 25 mm bore, 62 mm outside diameter, 17 mm width (0.984 x 2.441 x 0.669 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 29.3 kN, C0 15.8 kN and a 1.24 kN fatigue load limit Pu; the grease limiting speed is 13,000 r/min and the oil rating 17,000 r/min; mass about 230 g."
      },
      {
        "q": "How is the 7305 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 05 encodes the 25 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 62 mm OD and 17 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7305 support?",
        "a": "One 7305 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7305?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 13,000 r/min and the oil rating 17,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7305?",
        "a": "The 25/62/17 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 29.3 kN / C0 15.8 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7305",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7305-ACCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7305-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7305-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7305-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7305-BECBPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7305-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7305-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7305-BEY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7305",
      "7305-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7305B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7305B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 25,
    "D_mm": 62,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 27,
    "static_load_kN": 14.6,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.14,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "speed_oil_rpm": 15000,
    "weight_g": 234,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7305B belongs to the heavy-duty 7300 single-row family: the catalogue boundary dimensions read 25 / 62 / 17 mm (bore / OD / width). Reading the code: 73 is the single-row dimension series (heavy-duty 7300 single-row family), 05 encodes the 25 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). NTN prints 27 kN dynamic and 14.6 kN static for this size and a 1.14 kN fatigue load limit Pu. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Grease quantity matters as much as grade at 11,000 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "high-speed router, grinder and woodworking spindles",
      "small pump and compressor shafts with combined load",
      "servo and stepper motor shafts with axial preload",
      "bicycle and motorcycle wheel and steering positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At 25 mm bore the rings are thin-sectioned: press force must go through the ring being fitted, never through the balls, or the first damage is already in the raceway before the machine runs.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "The 11,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7305B without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 27/14.6 kN ratings and 1.14 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7305B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7305B?",
        "a": "7305B is a single-row angular contact ball bearing to ISO 15: 25 mm bore, 62 mm outside diameter, 17 mm width (0.984 x 2.441 x 0.669 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 27 kN, C0 14.6 kN and a 1.14 kN fatigue load limit Pu; the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min; mass about 234 g."
      },
      {
        "q": "How is the 7305B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 05 encodes the 25 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 62 mm OD and 17 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7305B support?",
        "a": "One 7305B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7305B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7305B?",
        "a": "The 25/62/17 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 27 kN / C0 14.6 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7305B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7305b",
      "7305B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7906",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7906",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 30,
    "D_mm": 47,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 8.35,
    "static_load_kN": 5.75,
    "cage_type": "polymer_PA66",
    "fatigue_load_limit_kN": 0.4,
    "limiting_speed_rpm": 14000,
    "max_rpm": 14000,
    "speed_oil_rpm": 19000,
    "weight_g": 58,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7906 is the 30 mm bore member of NTN's extra-light, high-speed 7900 single-row family, with a 47 mm outside diameter and 9 mm section width. Two fields make up the code — 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family) and 06 encodes the 30 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. On speed, the grease limiting speed is 14,000 r/min and the oil rating 19,000 r/min. For a 30 mm shaft with combined load, the practical shortlist is this series, its 7000-series standard section, and — where thrust reverses — a back-to-back pair rather than a single row. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 30 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 5.75 kN really covers the worst static case before substituting it for a 7000.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7906 without re-checking axial float, heat and housing width — the kinematics differ.",
      "On a 30 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The C0 of 5.75 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 8.35/5.75 kN ratings and 0.4 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7906; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7906?",
        "a": "7906 is a single-row angular contact ball bearing to ISO 15: 30 mm bore, 47 mm outside diameter, 9 mm width (1.181 x 1.85 x 0.354 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 8.35 kN, C0 5.75 kN and a 0.4 kN fatigue load limit Pu; the grease limiting speed is 14,000 r/min and the oil rating 19,000 r/min; mass about 58 g."
      },
      {
        "q": "How is the 7906 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 06 encodes the 30 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 47 mm OD and 9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7906 support?",
        "a": "One 7906 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7906?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 14,000 r/min and the oil rating 19,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7906?",
        "a": "The 30/47/9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 8.35 kN / C0 5.75 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7906",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7906"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7006-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7006",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 30,
    "D_mm": 55,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 15.4,
    "static_load_kN": 9.45,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.72,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "speed_oil_rpm": 18000,
    "weight_g": 135,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7006 is the 30 mm bore member of NTN's standard-section 7000 single-row family, with a 55 mm outside diameter and 13 mm section width. The designation breaks down as 70 is the single-row dimension series (standard-section 7000 single-row family); 06 encodes the 30 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 30 deg contact angle is the lever that turns the 9.45 kN static rating into useful one-direction thrust capacity. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Grease quantity matters as much as grade at 13,000 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 30 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The 13,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The C0 of 9.45 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "A 7006 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 15.4/9.45 kN ratings and 0.72 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7006; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7006?",
        "a": "7006 is a single-row angular contact ball bearing to ISO 15: 30 mm bore, 55 mm outside diameter, 13 mm width (1.181 x 2.165 x 0.512 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 15.4 kN, C0 9.45 kN and a 0.72 kN fatigue load limit Pu; the grease limiting speed is 13,000 r/min and the oil rating 18,000 r/min; mass about 135 g."
      },
      {
        "q": "How is the 7006 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 06 encodes the 30 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 55 mm OD and 13 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7006 support?",
        "a": "One 7006 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7006?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 13,000 r/min and the oil rating 18,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7006?",
        "a": "The 30/55/13 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 15.4 kN / C0 9.45 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7006",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=128",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7006",
      "7006-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5206S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5206S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 30,
    "D_mm": 62,
    "B_mm": 23.8,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 29.6,
    "static_load_kN": 21.1,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.3,
    "limiting_speed_rpm": 7100,
    "max_rpm": 7100,
    "speed_oil_rpm": 9500,
    "weight_g": 300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 5200S double-row family entry 5206S carries a 30 mm bore in a 62 mm outside diameter, 23.8 mm wide envelope. Reading the code: 52 is the double-row dimension series (medium-duty 5200S double-row family), 06 encodes the 30 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The static margin, C0 21.1 kN versus C 29.6 kN, is what supports slow oscillating duty and shock without immediate brinelling. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Grease quantity matters as much as grade at 7,100 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 30 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5206S without re-checking axial float, heat and housing width — the kinematics differ.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5206S without re-checking axial float, heat and housing width — the kinematics differ.",
      "Do not pair two random 5206S bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 29.6/21.1 kN ratings and 1.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5206S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5206S?",
        "a": "5206S is a double-row angular contact ball bearing to ISO 15: 30 mm bore, 62 mm outside diameter, 23.8 mm width (1.181 x 2.441 x 0.937 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 29.6 kN, C0 21.1 kN and a 1.3 kN fatigue load limit Pu; the grease limiting speed is 7,100 r/min and the oil rating 9,500 r/min; mass about 300 g."
      },
      {
        "q": "How is the 5206S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 06 encodes the 30 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 62 mm OD and 23.8 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5206S support?",
        "a": "5206S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5206S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,100 r/min and the oil rating 9,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5206S?",
        "a": "The 30/62/23.8 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 29.6 kN / C0 21.1 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5206S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5206s",
      "5206S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5206SCLLD",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5206SCLLD",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 30,
    "D_mm": 62,
    "B_mm": 23.8,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 25.2,
    "static_load_kN": 18.2,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.1,
    "limiting_speed_rpm": 6300,
    "max_rpm": 6300,
    "weight_g": 300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 5200S double-row family, 5206SCLLD measures 30 mm across the bore, 62 mm over the outer ring and 23.8 mm across the faces. Reading the code: 52 is the double-row dimension series (medium-duty 5200S double-row family), 06 encodes the 30 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. On speed, the grease limiting speed is 6,300 r/min and no oil rating is printed for this execution. Against a deep-groove bearing of the same 30 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 30 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed LLD contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Do not pair two random 5206SCLLD bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The C0 of 18.2 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 25.2/18.2 kN ratings and 1.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5206SCLLD; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5206SCLLD?",
        "a": "5206SCLLD is a sealed double-row angular contact ball bearing to ISO 15: 30 mm bore, 62 mm outside diameter, 23.8 mm width (1.181 x 2.441 x 0.937 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 25.2 kN, C0 18.2 kN and a 1.1 kN fatigue load limit Pu; the grease limiting speed is 6,300 r/min and no oil rating is printed for this execution; mass about 300 g."
      },
      {
        "q": "How is the 5206SCLLD designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 06 encodes the 30 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The 62 mm OD and 23.8 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5206SCLLD support?",
        "a": "5206SCLLD is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with contact rubber seals (grease-lubricated, no oil speed rating)."
      },
      {
        "q": "What lubrication speeds does NTN print for 5206SCLLD?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,300 r/min and no oil rating is printed for this execution. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5206SCLLD?",
        "a": "The 30/62/23.8 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 25.2 kN / C0 18.2 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5206SCLLD",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5206sclld",
      "5206SCLLD"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5206SCLLM",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5206SCLLM",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 30,
    "D_mm": 62,
    "B_mm": 23.8,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 25.2,
    "static_load_kN": 18.2,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.1,
    "limiting_speed_rpm": 7100,
    "max_rpm": 7100,
    "speed_oil_rpm": 9500,
    "weight_g": 300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5206SCLLM appears as a medium-duty 5200S double-row family bearing of 30 mm bore, 62 mm outside diameter and 23.8 mm width. The designation breaks down as 52 is the double-row dimension series (medium-duty 5200S double-row family); 06 encodes the 30 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The radial section height here is 16.0 mm, and the catalogue couples that with C 25.2 kN / C0 18.2 kN. Against a deep-groove bearing of the same 30 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 30 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed LLM non-contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 25.2/18.2 kN ratings and 1.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5206SCLLM; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5206SCLLM?",
        "a": "5206SCLLM is a sealed double-row angular contact ball bearing to ISO 15: 30 mm bore, 62 mm outside diameter, 23.8 mm width (1.181 x 2.441 x 0.937 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 25.2 kN, C0 18.2 kN and a 1.1 kN fatigue load limit Pu; the grease limiting speed is 7,100 r/min and the oil rating 9,500 r/min; mass about 300 g."
      },
      {
        "q": "How is the 5206SCLLM designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 06 encodes the 30 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The 62 mm OD and 23.8 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5206SCLLM support?",
        "a": "5206SCLLM is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with non-contact rubber seals that keep the shield-level speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5206SCLLM?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,100 r/min and the oil rating 9,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5206SCLLM?",
        "a": "The 30/62/23.8 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 25.2 kN / C0 18.2 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5206SCLLM",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5206scllm",
      "5206SCLLM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5206SCZZ",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5206SCZZ",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 30,
    "D_mm": 62,
    "B_mm": 23.8,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 25.2,
    "static_load_kN": 18.2,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.1,
    "limiting_speed_rpm": 7100,
    "max_rpm": 7100,
    "speed_oil_rpm": 9500,
    "weight_g": 300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5206SCZZ appears as a medium-duty 5200S double-row family bearing of 30 mm bore, 62 mm outside diameter and 23.8 mm width. Decoding 5206SCZZ: 52 is the double-row dimension series (medium-duty 5200S double-row family), with 06 encodes the 30 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. With C 25.2 kN and C0 18.2 kN, each mm of bore carries about 0.84 kN of dynamic rating. Against a deep-groove bearing of the same 30 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 30 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed ZZ shielded executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "A 5206SCZZ mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "On a 30 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 25.2/18.2 kN ratings and 1.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5206SCZZ; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5206SCZZ?",
        "a": "5206SCZZ is a sealed double-row angular contact ball bearing to ISO 15: 30 mm bore, 62 mm outside diameter, 23.8 mm width (1.181 x 2.441 x 0.937 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 25.2 kN, C0 18.2 kN and a 1.1 kN fatigue load limit Pu; the grease limiting speed is 7,100 r/min and the oil rating 9,500 r/min; mass about 300 g."
      },
      {
        "q": "How is the 5206SCZZ designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 06 encodes the 30 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The 62 mm OD and 23.8 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5206SCZZ support?",
        "a": "5206SCZZ is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with pressed-steel shields that keep the open-bearing speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5206SCZZ?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,100 r/min and the oil rating 9,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5206SCZZ?",
        "a": "The 30/62/23.8 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 25.2 kN / C0 18.2 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5206SCZZ",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5206sczz",
      "5206SCZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7206-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7206",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 30,
    "D_mm": 62,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 24.9,
    "static_load_kN": 14.8,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.16,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "speed_oil_rpm": 16000,
    "weight_g": 193,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7206 is the 30 mm bore member of NTN's medium-duty 7200 single-row family, with a 62 mm outside diameter and 16 mm section width. Decoding 7206: 72 is the single-row dimension series (medium-duty 7200 single-row family), with 06 encodes the 30 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. A 30 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 30 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 12,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 24.9/14.8 kN ratings and 1.16 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7206; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7206?",
        "a": "7206 is a single-row angular contact ball bearing to ISO 15: 30 mm bore, 62 mm outside diameter, 16 mm width (1.181 x 2.441 x 0.63 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 24.9 kN, C0 14.8 kN and a 1.16 kN fatigue load limit Pu; the grease limiting speed is 12,000 r/min and the oil rating 16,000 r/min; mass about 193 g."
      },
      {
        "q": "How is the 7206 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 06 encodes the 30 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 62 mm OD and 16 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7206 support?",
        "a": "One 7206 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7206?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 12,000 r/min and the oil rating 16,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7206?",
        "a": "The 30/62/16 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 24.9 kN / C0 14.8 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7206",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7206-ACCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7206-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7206-BECBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7206-BECBP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7206-BECBPH",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7206-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7206-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7206",
      "7206-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7206B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7206B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 30,
    "D_mm": 62,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 22.7,
    "static_load_kN": 13.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.06,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "speed_oil_rpm": 14000,
    "weight_g": 197,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7206B is an NTN single-row angular contact ball bearing: medium-duty 7200 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 30 x 62 x 16 mm. The designation breaks down as 72 is the single-row dimension series (medium-duty 7200 single-row family); 06 encodes the 30 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 40 deg contact angle is the lever that turns the 13.5 kN static rating into useful one-direction thrust capacity. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 30 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "A 7206B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 22.7/13.5 kN ratings and 1.06 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7206B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7206B?",
        "a": "7206B is a single-row angular contact ball bearing to ISO 15: 30 mm bore, 62 mm outside diameter, 16 mm width (1.181 x 2.441 x 0.63 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 22.7 kN, C0 13.5 kN and a 1.06 kN fatigue load limit Pu; the grease limiting speed is 11,000 r/min and the oil rating 14,000 r/min; mass about 197 g."
      },
      {
        "q": "How is the 7206B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 06 encodes the 30 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 62 mm OD and 16 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7206B support?",
        "a": "One 7206B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7206B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 11,000 r/min and the oil rating 14,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7206B?",
        "a": "The 30/62/16 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 22.7 kN / C0 13.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7206B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7206b",
      "7206B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5306S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5306S",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 30,
    "D_mm": 72,
    "B_mm": 30.2,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 40.5,
    "static_load_kN": 28.1,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.7,
    "limiting_speed_rpm": 6300,
    "max_rpm": 6300,
    "speed_oil_rpm": 8500,
    "weight_g": 570,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5306S appears as a heavy-duty 5300S double-row family bearing of 30 mm bore, 72 mm outside diameter and 30.2 mm width. NTN builds the number from 53 is the double-row dimension series (heavy-duty 5300S double-row family), then 06 encodes the 30 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. On speed, the grease limiting speed is 6,300 r/min and the oil rating 8,500 r/min. Size selection is usually finished by checking that the C0 of 28.1 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Grease quantity matters as much as grade at 6,300 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 30 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "Grease rated for deep-groove motor duty is not automatically right at 6,300 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The C0 of 28.1 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 40.5/28.1 kN ratings and 1.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5306S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5306S?",
        "a": "5306S is a double-row angular contact ball bearing to ISO 15: 30 mm bore, 72 mm outside diameter, 30.2 mm width (1.181 x 2.835 x 1.189 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 40.5 kN, C0 28.1 kN and a 1.7 kN fatigue load limit Pu; the grease limiting speed is 6,300 r/min and the oil rating 8,500 r/min; mass about 570 g."
      },
      {
        "q": "How is the 5306S designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 06 encodes the 30 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 72 mm OD and 30.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5306S support?",
        "a": "5306S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5306S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,300 r/min and the oil rating 8,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5306S?",
        "a": "The 30/72/30.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 40.5 kN / C0 28.1 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5306S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5306s",
      "5306S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5306SCLLD",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5306SCLLD",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 30,
    "D_mm": 72,
    "B_mm": 30.2,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 39,
    "static_load_kN": 28.7,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.7,
    "limiting_speed_rpm": 5300,
    "max_rpm": 5300,
    "weight_g": 570,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5306SCLLD appears as a heavy-duty 5300S double-row family bearing of 30 mm bore, 72 mm outside diameter and 30.2 mm width. The designation breaks down as 53 is the double-row dimension series (heavy-duty 5300S double-row family); 06 encodes the 30 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. Catalogue mass is about 570 g, which at this 21.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Against a deep-groove bearing of the same 30 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Grease quantity matters as much as grade at 5,300 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 30 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed LLD contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "On a 30 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 39/28.7 kN ratings and 1.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5306SCLLD; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5306SCLLD?",
        "a": "5306SCLLD is a sealed double-row angular contact ball bearing to ISO 15: 30 mm bore, 72 mm outside diameter, 30.2 mm width (1.181 x 2.835 x 1.189 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 39 kN, C0 28.7 kN and a 1.7 kN fatigue load limit Pu; the grease limiting speed is 5,300 r/min and no oil rating is printed for this execution; mass about 570 g."
      },
      {
        "q": "How is the 5306SCLLD designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 06 encodes the 30 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The 72 mm OD and 30.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5306SCLLD support?",
        "a": "5306SCLLD is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with contact rubber seals (grease-lubricated, no oil speed rating)."
      },
      {
        "q": "What lubrication speeds does NTN print for 5306SCLLD?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,300 r/min and no oil rating is printed for this execution. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5306SCLLD?",
        "a": "The 30/72/30.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 39 kN / C0 28.7 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5306SCLLD",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5306sclld",
      "5306SCLLD"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5306SCLLM",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5306SCLLM",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 30,
    "D_mm": 72,
    "B_mm": 30.2,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 39,
    "static_load_kN": 28.7,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.7,
    "limiting_speed_rpm": 6300,
    "max_rpm": 6300,
    "speed_oil_rpm": 8500,
    "weight_g": 570,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The heavy-duty 5300S double-row family entry 5306SCLLM carries a 30 mm bore in a 72 mm outside diameter, 30.2 mm wide envelope. NTN builds the number from 53 is the double-row dimension series (heavy-duty 5300S double-row family), then 06 encodes the 30 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. NTN prints 39 kN dynamic and 28.7 kN static for this size and a 1.7 kN fatigue load limit Pu. Against a deep-groove bearing of the same 30 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. A 30 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 30 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed LLM non-contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "Do not pair two random 5306SCLLM bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The C0 of 28.7 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5306SCLLM without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 39/28.7 kN ratings and 1.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5306SCLLM; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5306SCLLM?",
        "a": "5306SCLLM is a sealed double-row angular contact ball bearing to ISO 15: 30 mm bore, 72 mm outside diameter, 30.2 mm width (1.181 x 2.835 x 1.189 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 39 kN, C0 28.7 kN and a 1.7 kN fatigue load limit Pu; the grease limiting speed is 6,300 r/min and the oil rating 8,500 r/min; mass about 570 g."
      },
      {
        "q": "How is the 5306SCLLM designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 06 encodes the 30 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The 72 mm OD and 30.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5306SCLLM support?",
        "a": "5306SCLLM is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with non-contact rubber seals that keep the shield-level speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5306SCLLM?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,300 r/min and the oil rating 8,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5306SCLLM?",
        "a": "The 30/72/30.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 39 kN / C0 28.7 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5306SCLLM",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5306scllm",
      "5306SCLLM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5306SCZZ",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5306SCZZ",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 30,
    "D_mm": 72,
    "B_mm": 30.2,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 39,
    "static_load_kN": 28.7,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.7,
    "limiting_speed_rpm": 6300,
    "max_rpm": 6300,
    "speed_oil_rpm": 8500,
    "weight_g": 570,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 5306SCZZ belongs to the heavy-duty 5300S double-row family: the catalogue boundary dimensions read 30 / 72 / 30.2 mm (bore / OD / width). Two fields make up the code — 53 is the double-row dimension series (heavy-duty 5300S double-row family) and 06 encodes the 30 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The built-in back-to-back contact lines give the double-row bearing its two-direction thrust and moment capacity from one ring set. For a 30 mm shaft with combined load, the practical shortlist is this series, its neighbouring dimension series, and — where thrust reverses — a back-to-back pair rather than a single row. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 30 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed ZZ shielded executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "Grease rated for deep-groove motor duty is not automatically right at 6,300 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Do not pair two random 5306SCZZ bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "A 5306SCZZ mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 39/28.7 kN ratings and 1.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5306SCZZ; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5306SCZZ?",
        "a": "5306SCZZ is a sealed double-row angular contact ball bearing to ISO 15: 30 mm bore, 72 mm outside diameter, 30.2 mm width (1.181 x 2.835 x 1.189 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 39 kN, C0 28.7 kN and a 1.7 kN fatigue load limit Pu; the grease limiting speed is 6,300 r/min and the oil rating 8,500 r/min; mass about 570 g."
      },
      {
        "q": "How is the 5306SCZZ designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 06 encodes the 30 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The 72 mm OD and 30.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5306SCZZ support?",
        "a": "5306SCZZ is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with pressed-steel shields that keep the open-bearing speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5306SCZZ?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,300 r/min and the oil rating 8,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5306SCZZ?",
        "a": "The 30/72/30.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 39 kN / C0 28.7 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5306SCZZ",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5306sczz",
      "5306SCZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7306-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7306",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 30,
    "D_mm": 72,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 37.5,
    "static_load_kN": 22.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.75,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "speed_oil_rpm": 15000,
    "weight_g": 345,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty 7300 single-row family, 7306 measures 30 mm across the bore, 72 mm over the outer ring and 19 mm across the faces. Two fields make up the code — 73 is the single-row dimension series (heavy-duty 7300 single-row family) and 06 encodes the 30 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The radial section height here is 21.0 mm, and the catalogue couples that with C 37.5 kN / C0 22.3 kN. Choose the heavy-duty 7300 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 30 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "A 7306 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 37.5/22.3 kN ratings and 1.75 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7306; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7306?",
        "a": "7306 is a single-row angular contact ball bearing to ISO 15: 30 mm bore, 72 mm outside diameter, 19 mm width (1.181 x 2.835 x 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 37.5 kN, C0 22.3 kN and a 1.75 kN fatigue load limit Pu; the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min; mass about 345 g."
      },
      {
        "q": "How is the 7306 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 06 encodes the 30 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 72 mm OD and 19 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7306 support?",
        "a": "One 7306 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7306?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7306?",
        "a": "The 30/72/19 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 37.5 kN / C0 22.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7306",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7306-ACCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7306-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7306-BECBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7306-BECBP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7306-BECBY",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7306-BEGAPH",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7306-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7306",
      "7306-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7306B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7306B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 30,
    "D_mm": 72,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 34,
    "static_load_kN": 20.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.61,
    "limiting_speed_rpm": 9600,
    "max_rpm": 9600,
    "speed_oil_rpm": 13000,
    "weight_g": 352,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7306B is the 30 mm bore member of NTN's heavy-duty 7300 single-row family, with a 72 mm outside diameter and 19 mm section width. Decoding 7306B: 73 is the single-row dimension series (heavy-duty 7300 single-row family), with 06 encodes the 30 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Catalogue mass is about 352 g, which at this 21.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 30 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 9,600 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 34/20.5 kN ratings and 1.61 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7306B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7306B?",
        "a": "7306B is a single-row angular contact ball bearing to ISO 15: 30 mm bore, 72 mm outside diameter, 19 mm width (1.181 x 2.835 x 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 34 kN, C0 20.5 kN and a 1.61 kN fatigue load limit Pu; the grease limiting speed is 9,600 r/min and the oil rating 13,000 r/min; mass about 352 g."
      },
      {
        "q": "How is the 7306B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 06 encodes the 30 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 72 mm OD and 19 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7306B support?",
        "a": "One 7306B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7306B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 9,600 r/min and the oil rating 13,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7306B?",
        "a": "The 30/72/19 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 34 kN / C0 20.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7306B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7306b",
      "7306B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ306",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ306",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 30,
    "D_mm": 72,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 44,
    "static_load_kN": 57.5,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 2.46,
    "limiting_speed_rpm": 8000,
    "max_rpm": 8000,
    "speed_oil_rpm": 11000,
    "weight_g": 420,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 30 x 72 x 19 mm, NTN QJ306 sits in the heavy-duty QJ300 four-point family of the angular-contact programme. Reading the code: QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family), the last two digits 06 give the bore by the standard code table (30 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 30 mm bore give the working limits. ",
    "applications": [
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 30 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "A QJ306 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 8,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 44/57.5 kN ratings and 2.46 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ306; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ306?",
        "a": "QJ306 is a four-point contact ball bearing to ISO 15: 30 mm bore, 72 mm outside diameter, 19 mm width (1.181 x 2.835 x 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 44 kN, C0 57.5 kN and a 2.46 kN fatigue load limit Pu; the grease limiting speed is 8,000 r/min and the oil rating 11,000 r/min; mass about 420 g."
      },
      {
        "q": "How is the QJ306 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 06 give the bore by the standard code table (30 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 72 mm OD and 19 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ306 support?",
        "a": "QJ306 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ306?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 8,000 r/min and the oil rating 11,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ306?",
        "a": "The 30/72/19 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 44 kN / C0 57.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ306",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj306",
      "QJ306"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7907",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7907",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 35,
    "D_mm": 55,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 13.3,
    "static_load_kN": 8.85,
    "cage_type": "polymer_PA66",
    "fatigue_load_limit_kN": 0.64,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "speed_oil_rpm": 17000,
    "weight_g": 88,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the extra-light, high-speed 7900 single-row family, 7907 measures 35 mm across the bore, 55 mm over the outer ring and 10 mm across the faces. Decoding 7907: 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), with 07 encodes the 35 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. With C 13.3 kN and C0 8.85 kN, each mm of bore carries about 0.38 kN of dynamic rating. Against a deep-groove bearing of the same 35 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. A 35 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 35 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 8.85 kN really covers the worst static case before substituting it for a 7000.",
      "The C0 of 8.85 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "On a 35 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 13.3/8.85 kN ratings and 0.64 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7907; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7907?",
        "a": "7907 is a single-row angular contact ball bearing to ISO 15: 35 mm bore, 55 mm outside diameter, 10 mm width (1.378 x 2.165 x 0.394 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 13.3 kN, C0 8.85 kN and a 0.64 kN fatigue load limit Pu; the grease limiting speed is 13,000 r/min and the oil rating 17,000 r/min; mass about 88 g."
      },
      {
        "q": "How is the 7907 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 07 encodes the 35 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 55 mm OD and 10 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7907 support?",
        "a": "One 7907 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7907?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 13,000 r/min and the oil rating 17,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7907?",
        "a": "The 35/55/10 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 13.3 kN / C0 8.85 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7907",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7907"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7007-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7007",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 35,
    "D_mm": 62,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 19.4,
    "static_load_kN": 12.6,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 0.95,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "speed_oil_rpm": 16000,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the standard-section 7000 single-row family, 7007 measures 35 mm across the bore, 62 mm over the outer ring and 14 mm across the faces. Two fields make up the code — 70 is the single-row dimension series (standard-section 7000 single-row family) and 07 encodes the 35 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. On speed, the grease limiting speed is 12,000 r/min and the oil rating 16,000 r/min. For a 35 mm shaft with combined load, the practical shortlist is this series, its 7300-series heavier section, and — where thrust reverses — a back-to-back pair rather than a single row. Grease quantity matters as much as grade at 12,000 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 35 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Grease rated for deep-groove motor duty is not automatically right at 12,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The C0 of 12.6 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 19.4/12.6 kN ratings and 0.95 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7007; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7007?",
        "a": "7007 is a single-row angular contact ball bearing to ISO 15: 35 mm bore, 62 mm outside diameter, 14 mm width (1.378 x 2.441 x 0.551 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 19.4 kN, C0 12.6 kN and a 0.95 kN fatigue load limit Pu; the grease limiting speed is 12,000 r/min and the oil rating 16,000 r/min; mass about 180 g."
      },
      {
        "q": "How is the 7007 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 07 encodes the 35 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 62 mm OD and 14 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7007 support?",
        "a": "One 7007 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7007?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 12,000 r/min and the oil rating 16,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7007?",
        "a": "The 35/62/14 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 19.4 kN / C0 12.6 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7007",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7007",
      "7007-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5207S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5207S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 35,
    "D_mm": 72,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 39,
    "static_load_kN": 28.7,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.7,
    "limiting_speed_rpm": 6300,
    "max_rpm": 6300,
    "speed_oil_rpm": 8000,
    "weight_g": 460,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 5200S double-row family, 5207S measures 35 mm across the bore, 72 mm over the outer ring and 27 mm across the faces. Decoding 5207S: 52 is the double-row dimension series (medium-duty 5200S double-row family), with 07 encodes the 35 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. Catalogue dynamic rating C is 39 kN against C0 28.7 kN — a C0/C ratio of 0.74 that is typical of an angular-contact contact ellipse. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 35 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 39/28.7 kN ratings and 1.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5207S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5207S?",
        "a": "5207S is a double-row angular contact ball bearing to ISO 15: 35 mm bore, 72 mm outside diameter, 27 mm width (1.378 x 2.835 x 1.063 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 39 kN, C0 28.7 kN and a 1.7 kN fatigue load limit Pu; the grease limiting speed is 6,300 r/min and the oil rating 8,000 r/min; mass about 460 g."
      },
      {
        "q": "How is the 5207S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 07 encodes the 35 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 72 mm OD and 27 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5207S support?",
        "a": "5207S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5207S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,300 r/min and the oil rating 8,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5207S?",
        "a": "The 35/72/27 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 39 kN / C0 28.7 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5207S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5207s",
      "5207S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5207SCLLD",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5207SCLLD",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 35,
    "D_mm": 72,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 34,
    "static_load_kN": 25.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.5,
    "limiting_speed_rpm": 5300,
    "max_rpm": 5300,
    "weight_g": 460,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 5200S double-row family, 5207SCLLD measures 35 mm across the bore, 72 mm over the outer ring and 27 mm across the faces. The designation breaks down as 52 is the double-row dimension series (medium-duty 5200S double-row family); 07 encodes the 35 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. NTN prints 34 kN dynamic and 25.3 kN static for this size and a 1.5 kN fatigue load limit Pu. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 35 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed LLD contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5207SCLLD without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 34/25.3 kN ratings and 1.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5207SCLLD; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5207SCLLD?",
        "a": "5207SCLLD is a sealed double-row angular contact ball bearing to ISO 15: 35 mm bore, 72 mm outside diameter, 27 mm width (1.378 x 2.835 x 1.063 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 34 kN, C0 25.3 kN and a 1.5 kN fatigue load limit Pu; the grease limiting speed is 5,300 r/min and no oil rating is printed for this execution; mass about 460 g."
      },
      {
        "q": "How is the 5207SCLLD designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 07 encodes the 35 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The 72 mm OD and 27 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5207SCLLD support?",
        "a": "5207SCLLD is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with contact rubber seals (grease-lubricated, no oil speed rating)."
      },
      {
        "q": "What lubrication speeds does NTN print for 5207SCLLD?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,300 r/min and no oil rating is printed for this execution. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5207SCLLD?",
        "a": "The 35/72/27 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 34 kN / C0 25.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5207SCLLD",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5207sclld",
      "5207SCLLD"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5207SCLLM",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5207SCLLM",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 35,
    "D_mm": 72,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 34,
    "static_load_kN": 25.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.5,
    "limiting_speed_rpm": 6300,
    "max_rpm": 6300,
    "speed_oil_rpm": 8500,
    "weight_g": 460,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5207SCLLM appears as a medium-duty 5200S double-row family bearing of 35 mm bore, 72 mm outside diameter and 27 mm width. NTN builds the number from 52 is the double-row dimension series (medium-duty 5200S double-row family), then 07 encodes the 35 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. Catalogue dynamic rating C is 34 kN against C0 25.3 kN — a C0/C ratio of 0.74 that is typical of an angular-contact contact ellipse. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 35 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed LLM non-contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5207SCLLM without re-checking axial float, heat and housing width — the kinematics differ.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 34/25.3 kN ratings and 1.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5207SCLLM; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5207SCLLM?",
        "a": "5207SCLLM is a sealed double-row angular contact ball bearing to ISO 15: 35 mm bore, 72 mm outside diameter, 27 mm width (1.378 x 2.835 x 1.063 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 34 kN, C0 25.3 kN and a 1.5 kN fatigue load limit Pu; the grease limiting speed is 6,300 r/min and the oil rating 8,500 r/min; mass about 460 g."
      },
      {
        "q": "How is the 5207SCLLM designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 07 encodes the 35 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The 72 mm OD and 27 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5207SCLLM support?",
        "a": "5207SCLLM is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with non-contact rubber seals that keep the shield-level speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5207SCLLM?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,300 r/min and the oil rating 8,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5207SCLLM?",
        "a": "The 35/72/27 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 34 kN / C0 25.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5207SCLLM",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5207scllm",
      "5207SCLLM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5207SCZZ",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5207SCZZ",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 35,
    "D_mm": 72,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 34,
    "static_load_kN": 25.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.5,
    "limiting_speed_rpm": 6300,
    "max_rpm": 6300,
    "speed_oil_rpm": 8500,
    "weight_g": 460,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 5207SCZZ belongs to the medium-duty 5200S double-row family: the catalogue boundary dimensions read 35 / 72 / 27 mm (bore / OD / width). The designation breaks down as 52 is the double-row dimension series (medium-duty 5200S double-row family); 07 encodes the 35 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The static margin, C0 25.3 kN versus C 34 kN, is what supports slow oscillating duty and shock without immediate brinelling. Choose the medium-duty 5200S double-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 35 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed ZZ shielded executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5207SCZZ without re-checking axial float, heat and housing width — the kinematics differ.",
      "Grease rated for deep-groove motor duty is not automatically right at 6,300 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Do not pair two random 5207SCZZ bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 34/25.3 kN ratings and 1.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5207SCZZ; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5207SCZZ?",
        "a": "5207SCZZ is a sealed double-row angular contact ball bearing to ISO 15: 35 mm bore, 72 mm outside diameter, 27 mm width (1.378 x 2.835 x 1.063 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 34 kN, C0 25.3 kN and a 1.5 kN fatigue load limit Pu; the grease limiting speed is 6,300 r/min and the oil rating 8,500 r/min; mass about 460 g."
      },
      {
        "q": "How is the 5207SCZZ designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 07 encodes the 35 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The 72 mm OD and 27 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5207SCZZ support?",
        "a": "5207SCZZ is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with pressed-steel shields that keep the open-bearing speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5207SCZZ?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,300 r/min and the oil rating 8,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5207SCZZ?",
        "a": "The 35/72/27 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 34 kN / C0 25.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5207SCZZ",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5207sczz",
      "5207SCZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7207-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7207",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 35,
    "D_mm": 72,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 33,
    "static_load_kN": 20.1,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.57,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "speed_oil_rpm": 14000,
    "weight_g": 281,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 7200 single-row family, 7207 measures 35 mm across the bore, 72 mm over the outer ring and 17 mm across the faces. The designation breaks down as 72 is the single-row dimension series (medium-duty 7200 single-row family); 07 encodes the 35 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue mass is about 281 g, which at this 18.5 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Size selection is usually finished by checking that the C0 of 20.1 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. A 35 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 35 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The C0 of 20.1 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Grease rated for deep-groove motor duty is not automatically right at 11,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 33/20.1 kN ratings and 1.57 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7207; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7207?",
        "a": "7207 is a single-row angular contact ball bearing to ISO 15: 35 mm bore, 72 mm outside diameter, 17 mm width (1.378 x 2.835 x 0.669 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 33 kN, C0 20.1 kN and a 1.57 kN fatigue load limit Pu; the grease limiting speed is 11,000 r/min and the oil rating 14,000 r/min; mass about 281 g."
      },
      {
        "q": "How is the 7207 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 07 encodes the 35 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 72 mm OD and 17 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7207 support?",
        "a": "One 7207 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7207?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 11,000 r/min and the oil rating 14,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7207?",
        "a": "The 35/72/17 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 33 kN / C0 20.1 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7207",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7207-ACCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7207-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7207-BECBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7207-BECBP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7207-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7207-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7207",
      "7207-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7207B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7207B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 35,
    "D_mm": 72,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 30,
    "static_load_kN": 18.4,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.44,
    "limiting_speed_rpm": 9300,
    "max_rpm": 9300,
    "speed_oil_rpm": 12000,
    "weight_g": 287,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 7200 single-row family entry 7207B carries a 35 mm bore in a 72 mm outside diameter, 17 mm wide envelope. Two fields make up the code — 72 is the single-row dimension series (medium-duty 7200 single-row family) and 07 encodes the 35 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). With C 30 kN and C0 18.4 kN, each mm of bore carries about 0.86 kN of dynamic rating. For a 35 mm shaft with combined load, the practical shortlist is this series, its 7300-series heavier section, and — where thrust reverses — a back-to-back pair rather than a single row. Heat-mounting to 80-90 deg C is the clean route onto a 35 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 35 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7207B without re-checking axial float, heat and housing width — the kinematics differ.",
      "On a 35 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "On a 35 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 30/18.4 kN ratings and 1.44 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7207B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7207B?",
        "a": "7207B is a single-row angular contact ball bearing to ISO 15: 35 mm bore, 72 mm outside diameter, 17 mm width (1.378 x 2.835 x 0.669 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 30 kN, C0 18.4 kN and a 1.44 kN fatigue load limit Pu; the grease limiting speed is 9,300 r/min and the oil rating 12,000 r/min; mass about 287 g."
      },
      {
        "q": "How is the 7207B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 07 encodes the 35 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 72 mm OD and 17 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7207B support?",
        "a": "One 7207B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7207B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 9,300 r/min and the oil rating 12,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7207B?",
        "a": "The 35/72/17 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 30 kN / C0 18.4 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7207B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7207b",
      "7207B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5307S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5307S",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 35,
    "D_mm": 80,
    "B_mm": 34.9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 51,
    "static_load_kN": 36,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.2,
    "limiting_speed_rpm": 5600,
    "max_rpm": 5600,
    "speed_oil_rpm": 7500,
    "weight_g": 760,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 35 x 80 x 34.9 mm, NTN 5307S sits in the heavy-duty 5300S double-row family of the angular-contact programme. Reading the code: 53 is the double-row dimension series (heavy-duty 5300S double-row family), 07 encodes the 35 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The static margin, C0 36 kN versus C 51 kN, is what supports slow oscillating duty and shock without immediate brinelling. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 35 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "On a 35 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 5,600 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Do not pair two random 5307S bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 51/36 kN ratings and 2.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5307S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5307S?",
        "a": "5307S is a double-row angular contact ball bearing to ISO 15: 35 mm bore, 80 mm outside diameter, 34.9 mm width (1.378 x 3.15 x 1.374 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 51 kN, C0 36 kN and a 2.2 kN fatigue load limit Pu; the grease limiting speed is 5,600 r/min and the oil rating 7,500 r/min; mass about 760 g."
      },
      {
        "q": "How is the 5307S designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 07 encodes the 35 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 80 mm OD and 34.9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5307S support?",
        "a": "5307S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5307S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,600 r/min and the oil rating 7,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5307S?",
        "a": "The 35/80/34.9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 51 kN / C0 36 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5307S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5307s",
      "5307S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5307SCLLD",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5307SCLLD",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 35,
    "D_mm": 80,
    "B_mm": 34.9,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 44,
    "static_load_kN": 33.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2,
    "limiting_speed_rpm": 4800,
    "max_rpm": 4800,
    "weight_g": 790,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5307SCLLD appears as a heavy-duty 5300S double-row family bearing of 35 mm bore, 80 mm outside diameter and 34.9 mm width. NTN builds the number from 53 is the double-row dimension series (heavy-duty 5300S double-row family), then 07 encodes the 35 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The grease limiting speed is 4,800 r/min and no oil rating is printed for this execution. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. A 35 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 35 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed LLD contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "On a 35 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Grease rated for deep-groove motor duty is not automatically right at 4,800 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 44/33.5 kN ratings and 2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5307SCLLD; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5307SCLLD?",
        "a": "5307SCLLD is a sealed double-row angular contact ball bearing to ISO 15: 35 mm bore, 80 mm outside diameter, 34.9 mm width (1.378 x 3.15 x 1.374 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 44 kN, C0 33.5 kN and a 2 kN fatigue load limit Pu; the grease limiting speed is 4,800 r/min and no oil rating is printed for this execution; mass about 790 g."
      },
      {
        "q": "How is the 5307SCLLD designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 07 encodes the 35 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The 80 mm OD and 34.9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5307SCLLD support?",
        "a": "5307SCLLD is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with contact rubber seals (grease-lubricated, no oil speed rating)."
      },
      {
        "q": "What lubrication speeds does NTN print for 5307SCLLD?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,800 r/min and no oil rating is printed for this execution. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5307SCLLD?",
        "a": "The 35/80/34.9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 44 kN / C0 33.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5307SCLLD",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5307sclld",
      "5307SCLLD"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5307SCLLM",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5307SCLLM",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 35,
    "D_mm": 80,
    "B_mm": 34.9,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 44,
    "static_load_kN": 33.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2,
    "limiting_speed_rpm": 5600,
    "max_rpm": 5600,
    "speed_oil_rpm": 7500,
    "weight_g": 790,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The heavy-duty 5300S double-row family entry 5307SCLLM carries a 35 mm bore in a 80 mm outside diameter, 34.9 mm wide envelope. Decoding 5307SCLLM: 53 is the double-row dimension series (heavy-duty 5300S double-row family), with 07 encodes the 35 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. With C 44 kN and C0 33.5 kN, each mm of bore carries about 1.26 kN of dynamic rating. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 35 mm bore give the working limits. ",
    "applications": [
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 35 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed LLM non-contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "A 5307SCLLM mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 5,600 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "On a 35 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 44/33.5 kN ratings and 2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5307SCLLM; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5307SCLLM?",
        "a": "5307SCLLM is a sealed double-row angular contact ball bearing to ISO 15: 35 mm bore, 80 mm outside diameter, 34.9 mm width (1.378 x 3.15 x 1.374 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 44 kN, C0 33.5 kN and a 2 kN fatigue load limit Pu; the grease limiting speed is 5,600 r/min and the oil rating 7,500 r/min; mass about 790 g."
      },
      {
        "q": "How is the 5307SCLLM designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 07 encodes the 35 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The 80 mm OD and 34.9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5307SCLLM support?",
        "a": "5307SCLLM is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with non-contact rubber seals that keep the shield-level speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5307SCLLM?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,600 r/min and the oil rating 7,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5307SCLLM?",
        "a": "The 35/80/34.9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 44 kN / C0 33.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5307SCLLM",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5307scllm",
      "5307SCLLM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5307SCZZ",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5307SCZZ",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 35,
    "D_mm": 80,
    "B_mm": 34.9,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 44,
    "static_load_kN": 33.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2,
    "limiting_speed_rpm": 5600,
    "max_rpm": 5600,
    "speed_oil_rpm": 7500,
    "weight_g": 790,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5307SCZZ appears as a heavy-duty 5300S double-row family bearing of 35 mm bore, 80 mm outside diameter and 34.9 mm width. NTN builds the number from 53 is the double-row dimension series (heavy-duty 5300S double-row family), then 07 encodes the 35 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. With C 44 kN and C0 33.5 kN, each mm of bore carries about 1.26 kN of dynamic rating. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Heat-mounting to 80-90 deg C is the clean route onto a 35 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 35 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed ZZ shielded executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "A 5307SCZZ mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The C0 of 33.5 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "On a 35 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 44/33.5 kN ratings and 2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5307SCZZ; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5307SCZZ?",
        "a": "5307SCZZ is a sealed double-row angular contact ball bearing to ISO 15: 35 mm bore, 80 mm outside diameter, 34.9 mm width (1.378 x 3.15 x 1.374 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 44 kN, C0 33.5 kN and a 2 kN fatigue load limit Pu; the grease limiting speed is 5,600 r/min and the oil rating 7,500 r/min; mass about 790 g."
      },
      {
        "q": "How is the 5307SCZZ designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 07 encodes the 35 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The 80 mm OD and 34.9 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5307SCZZ support?",
        "a": "5307SCZZ is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with pressed-steel shields that keep the open-bearing speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5307SCZZ?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,600 r/min and the oil rating 7,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5307SCZZ?",
        "a": "The 35/80/34.9 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 44 kN / C0 33.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5307SCZZ",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5307sczz",
      "5307SCZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7307-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7307",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 35,
    "D_mm": 80,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 44,
    "static_load_kN": 26.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.05,
    "limiting_speed_rpm": 9800,
    "max_rpm": 9800,
    "speed_oil_rpm": 13000,
    "weight_g": 462,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7307 is an NTN single-row angular contact ball bearing: heavy-duty 7300 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 35 x 80 x 21 mm. NTN builds the number from 73 is the single-row dimension series (heavy-duty 7300 single-row family), then 07 encodes the 35 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 30 deg contact angle is the lever that turns the 26.3 kN static rating into useful one-direction thrust capacity. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 35 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "A 7307 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 44/26.3 kN ratings and 2.05 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7307; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7307?",
        "a": "7307 is a single-row angular contact ball bearing to ISO 15: 35 mm bore, 80 mm outside diameter, 21 mm width (1.378 x 3.15 x 0.827 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 44 kN, C0 26.3 kN and a 2.05 kN fatigue load limit Pu; the grease limiting speed is 9,800 r/min and the oil rating 13,000 r/min; mass about 462 g."
      },
      {
        "q": "How is the 7307 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 07 encodes the 35 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 80 mm OD and 21 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7307 support?",
        "a": "One 7307 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7307?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 9,800 r/min and the oil rating 13,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7307?",
        "a": "The 35/80/21 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 44 kN / C0 26.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7307",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7307-ACCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7307-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7307-BECBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7307-BECBP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7307-BECBY",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7307-BEGAPH",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7307-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7307",
      "7307-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7307B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7307B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 35,
    "D_mm": 80,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 40.5,
    "static_load_kN": 24.2,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.89,
    "limiting_speed_rpm": 8400,
    "max_rpm": 8400,
    "speed_oil_rpm": 11000,
    "weight_g": 469,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7307B appears as a heavy-duty 7300 single-row family bearing of 35 mm bore, 80 mm outside diameter and 21 mm width. The designation breaks down as 73 is the single-row dimension series (heavy-duty 7300 single-row family); 07 encodes the 35 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 40 deg contact angle is the lever that turns the 24.2 kN static rating into useful one-direction thrust capacity. The 35/80/21 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Heat-mounting to 80-90 deg C is the clean route onto a 35 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 35 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Grease rated for deep-groove motor duty is not automatically right at 8,400 r/min with preload; check the grease speed factor against the catalogue figure.",
      "A 7307B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "A 7307B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 40.5/24.2 kN ratings and 1.89 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7307B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7307B?",
        "a": "7307B is a single-row angular contact ball bearing to ISO 15: 35 mm bore, 80 mm outside diameter, 21 mm width (1.378 x 3.15 x 0.827 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 40.5 kN, C0 24.2 kN and a 1.89 kN fatigue load limit Pu; the grease limiting speed is 8,400 r/min and the oil rating 11,000 r/min; mass about 469 g."
      },
      {
        "q": "How is the 7307B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 07 encodes the 35 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 80 mm OD and 21 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7307B support?",
        "a": "One 7307B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7307B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 8,400 r/min and the oil rating 11,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7307B?",
        "a": "The 35/80/21 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 40.5 kN / C0 24.2 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7307B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7307b",
      "7307B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ307",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ307",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 35,
    "D_mm": 80,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 55,
    "static_load_kN": 73,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 3.15,
    "limiting_speed_rpm": 7000,
    "max_rpm": 7000,
    "speed_oil_rpm": 9300,
    "weight_g": 570,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "QJ307 is the 35 mm bore member of NTN's heavy-duty QJ300 four-point family, with a 80 mm outside diameter and 21 mm section width. Two fields make up the code — QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family) and the last two digits 07 give the bore by the standard code table (35 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. Catalogue mass is about 570 g, which at this 22.5 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Choose the heavy-duty QJ300 four-point family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Heat-mounting to 80-90 deg C is the clean route onto a 35 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 35 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "A QJ307 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 7,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 55/73 kN ratings and 3.15 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ307; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ307?",
        "a": "QJ307 is a four-point contact ball bearing to ISO 15: 35 mm bore, 80 mm outside diameter, 21 mm width (1.378 x 3.15 x 0.827 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 55 kN, C0 73 kN and a 3.15 kN fatigue load limit Pu; the grease limiting speed is 7,000 r/min and the oil rating 9,300 r/min; mass about 570 g."
      },
      {
        "q": "How is the QJ307 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 07 give the bore by the standard code table (35 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 80 mm OD and 21 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ307 support?",
        "a": "QJ307 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ307?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,000 r/min and the oil rating 9,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ307?",
        "a": "The 35/80/21 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 55 kN / C0 73 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ307",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj307",
      "QJ307"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7908",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7908",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 62,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 14,
    "static_load_kN": 10.2,
    "cage_type": "polymer_PA66",
    "fatigue_load_limit_kN": 0.7,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "speed_oil_rpm": 15000,
    "weight_g": 130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7908 is an NTN single-row angular contact ball bearing: extra-light, high-speed 7900 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 40 x 62 x 12 mm. NTN builds the number from 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), then 08 encodes the 40 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The static margin, C0 10.2 kN versus C 14 kN, is what supports slow oscillating duty and shock without immediate brinelling. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 10.2 kN really covers the worst static case before substituting it for a 7000.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7908 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Do not pair two random 7908 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 14/10.2 kN ratings and 0.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7908; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7908?",
        "a": "7908 is a single-row angular contact ball bearing to ISO 15: 40 mm bore, 62 mm outside diameter, 12 mm width (1.575 x 2.441 x 0.472 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 14 kN, C0 10.2 kN and a 0.7 kN fatigue load limit Pu; the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min; mass about 130 g."
      },
      {
        "q": "How is the 7908 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 08 encodes the 40 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 62 mm OD and 12 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7908 support?",
        "a": "One 7908 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7908?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 11,000 r/min and the oil rating 15,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7908?",
        "a": "The 40/62/12 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 14 kN / C0 10.2 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7908",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7908"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7008-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7008",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 68,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 20.8,
    "static_load_kN": 14.6,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.07,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "speed_oil_rpm": 14000,
    "weight_g": 222,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7008 is the 40 mm bore member of NTN's standard-section 7000 single-row family, with a 68 mm outside diameter and 15 mm section width. NTN builds the number from 70 is the single-row dimension series (standard-section 7000 single-row family), then 08 encodes the 40 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The static margin, C0 14.6 kN versus C 20.8 kN, is what supports slow oscillating duty and shock without immediate brinelling. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. A 40 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A 7008 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 10,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Do not pair two random 7008 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 20.8/14.6 kN ratings and 1.07 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7008; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7008?",
        "a": "7008 is a single-row angular contact ball bearing to ISO 15: 40 mm bore, 68 mm outside diameter, 15 mm width (1.575 x 2.677 x 0.591 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 20.8 kN, C0 14.6 kN and a 1.07 kN fatigue load limit Pu; the grease limiting speed is 10,000 r/min and the oil rating 14,000 r/min; mass about 222 g."
      },
      {
        "q": "How is the 7008 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 08 encodes the 40 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 68 mm OD and 15 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7008 support?",
        "a": "One 7008 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7008?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 10,000 r/min and the oil rating 14,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7008?",
        "a": "The 40/68/15 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 20.8 kN / C0 14.6 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7008",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7008",
      "7008-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5208S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5208S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 30.2,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 44,
    "static_load_kN": 33.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2,
    "limiting_speed_rpm": 5600,
    "max_rpm": 5600,
    "speed_oil_rpm": 7100,
    "weight_g": 620,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 5208S belongs to the medium-duty 5200S double-row family: the catalogue boundary dimensions read 40 / 80 / 30.2 mm (bore / OD / width). The designation breaks down as 52 is the double-row dimension series (medium-duty 5200S double-row family); 08 encodes the 40 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. NTN prints 44 kN dynamic and 33.5 kN static for this size and a 2 kN fatigue load limit Pu. The 40/80/30.2 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Heat-mounting to 80-90 deg C is the clean route onto a 40 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "Do not pair two random 5208S bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "On a 40 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5208S without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 44/33.5 kN ratings and 2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5208S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5208S?",
        "a": "5208S is a double-row angular contact ball bearing to ISO 15: 40 mm bore, 80 mm outside diameter, 30.2 mm width (1.575 x 3.15 x 1.189 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 44 kN, C0 33.5 kN and a 2 kN fatigue load limit Pu; the grease limiting speed is 5,600 r/min and the oil rating 7,100 r/min; mass about 620 g."
      },
      {
        "q": "How is the 5208S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 08 encodes the 40 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 80 mm OD and 30.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5208S support?",
        "a": "5208S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5208S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,600 r/min and the oil rating 7,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5208S?",
        "a": "The 40/80/30.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 44 kN / C0 33.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5208S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5208s",
      "5208S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5208SCLLD",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5208SCLLD",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 30.2,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 36.5,
    "static_load_kN": 29,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.7,
    "limiting_speed_rpm": 4800,
    "max_rpm": 4800,
    "weight_g": 630,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 40 x 80 x 30.2 mm, NTN 5208SCLLD sits in the medium-duty 5200S double-row family of the angular-contact programme. Reading the code: 52 is the double-row dimension series (medium-duty 5200S double-row family), 08 encodes the 40 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The radial section height here is 20.0 mm, and the catalogue couples that with C 36.5 kN / C0 29 kN. Choose the medium-duty 5200S double-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed LLD contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 36.5/29 kN ratings and 1.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5208SCLLD; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5208SCLLD?",
        "a": "5208SCLLD is a sealed double-row angular contact ball bearing to ISO 15: 40 mm bore, 80 mm outside diameter, 30.2 mm width (1.575 x 3.15 x 1.189 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 36.5 kN, C0 29 kN and a 1.7 kN fatigue load limit Pu; the grease limiting speed is 4,800 r/min and no oil rating is printed for this execution; mass about 630 g."
      },
      {
        "q": "How is the 5208SCLLD designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 08 encodes the 40 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The 80 mm OD and 30.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5208SCLLD support?",
        "a": "5208SCLLD is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with contact rubber seals (grease-lubricated, no oil speed rating)."
      },
      {
        "q": "What lubrication speeds does NTN print for 5208SCLLD?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,800 r/min and no oil rating is printed for this execution. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5208SCLLD?",
        "a": "The 40/80/30.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 36.5 kN / C0 29 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5208SCLLD",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5208sclld",
      "5208SCLLD"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5208SCLLM",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5208SCLLM",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 30.2,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 36.5,
    "static_load_kN": 29,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.7,
    "limiting_speed_rpm": 5600,
    "max_rpm": 5600,
    "speed_oil_rpm": 7100,
    "weight_g": 630,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 5200S double-row family, 5208SCLLM measures 40 mm across the bore, 80 mm over the outer ring and 30.2 mm across the faces. The designation breaks down as 52 is the double-row dimension series (medium-duty 5200S double-row family); 08 encodes the 40 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Choose the medium-duty 5200S double-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed LLM non-contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "A 5208SCLLM mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Grease rated for deep-groove motor duty is not automatically right at 5,600 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 5,600 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 36.5/29 kN ratings and 1.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5208SCLLM; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5208SCLLM?",
        "a": "5208SCLLM is a sealed double-row angular contact ball bearing to ISO 15: 40 mm bore, 80 mm outside diameter, 30.2 mm width (1.575 x 3.15 x 1.189 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 36.5 kN, C0 29 kN and a 1.7 kN fatigue load limit Pu; the grease limiting speed is 5,600 r/min and the oil rating 7,100 r/min; mass about 630 g."
      },
      {
        "q": "How is the 5208SCLLM designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 08 encodes the 40 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The 80 mm OD and 30.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5208SCLLM support?",
        "a": "5208SCLLM is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with non-contact rubber seals that keep the shield-level speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5208SCLLM?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,600 r/min and the oil rating 7,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5208SCLLM?",
        "a": "The 40/80/30.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 36.5 kN / C0 29 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5208SCLLM",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5208scllm",
      "5208SCLLM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5208SCZZ",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5208SCZZ",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 30.2,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 36.5,
    "static_load_kN": 29,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.7,
    "limiting_speed_rpm": 5600,
    "max_rpm": 5600,
    "speed_oil_rpm": 7100,
    "weight_g": 630,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5208SCZZ appears as a medium-duty 5200S double-row family bearing of 40 mm bore, 80 mm outside diameter and 30.2 mm width. Two fields make up the code — 52 is the double-row dimension series (medium-duty 5200S double-row family) and 08 encodes the 40 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. Catalogue dynamic rating C is 36.5 kN against C0 29 kN — a C0/C ratio of 0.79 that is typical of an angular-contact contact ellipse. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Heat-mounting to 80-90 deg C is the clean route onto a 40 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed ZZ shielded executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "Do not pair two random 5208SCZZ bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "On a 40 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 36.5/29 kN ratings and 1.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5208SCZZ; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5208SCZZ?",
        "a": "5208SCZZ is a sealed double-row angular contact ball bearing to ISO 15: 40 mm bore, 80 mm outside diameter, 30.2 mm width (1.575 x 3.15 x 1.189 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 36.5 kN, C0 29 kN and a 1.7 kN fatigue load limit Pu; the grease limiting speed is 5,600 r/min and the oil rating 7,100 r/min; mass about 630 g."
      },
      {
        "q": "How is the 5208SCZZ designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 08 encodes the 40 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The 80 mm OD and 30.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5208SCZZ support?",
        "a": "5208SCZZ is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with pressed-steel shields that keep the open-bearing speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5208SCZZ?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,600 r/min and the oil rating 7,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5208SCZZ?",
        "a": "The 40/80/30.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 36.5 kN / C0 29 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5208SCZZ",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5208sczz",
      "5208SCZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7208-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7208",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 39,
    "static_load_kN": 25.1,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.97,
    "limiting_speed_rpm": 9600,
    "max_rpm": 9600,
    "speed_oil_rpm": 13000,
    "weight_g": 355,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7208 is an NTN single-row angular contact ball bearing: medium-duty 7200 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 40 x 80 x 18 mm. Two fields make up the code — 72 is the single-row dimension series (medium-duty 7200 single-row family) and 08 encodes the 40 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The radial section height here is 20.0 mm, and the catalogue couples that with C 39 kN / C0 25.1 kN. The 40/80/18 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. A 40 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The 9,600 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "On a 40 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 39/25.1 kN ratings and 1.97 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7208; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7208?",
        "a": "7208 is a single-row angular contact ball bearing to ISO 15: 40 mm bore, 80 mm outside diameter, 18 mm width (1.575 x 3.15 x 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 39 kN, C0 25.1 kN and a 1.97 kN fatigue load limit Pu; the grease limiting speed is 9,600 r/min and the oil rating 13,000 r/min; mass about 355 g."
      },
      {
        "q": "How is the 7208 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 08 encodes the 40 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 80 mm OD and 18 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7208 support?",
        "a": "One 7208 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7208?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 9,600 r/min and the oil rating 13,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7208?",
        "a": "The 40/80/18 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 39 kN / C0 25.1 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7208",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7208-ACCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7208-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7208-BECBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7208-BECBP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7208-BECBPH",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7208-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7208-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7208",
      "7208-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7208B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7208B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 35.5,
    "static_load_kN": 23,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.8,
    "limiting_speed_rpm": 8300,
    "max_rpm": 8300,
    "speed_oil_rpm": 11000,
    "weight_g": 375,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 7200 single-row family, 7208B measures 40 mm across the bore, 80 mm over the outer ring and 18 mm across the faces. NTN builds the number from 72 is the single-row dimension series (medium-duty 7200 single-row family), then 08 encodes the 40 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The oil rating of 11,000 r/min sits 2,700 r/min above the 8,300 r/min grease figure — a 1.33x step that says how much headroom oil cooling buys. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 40 mm bore give the working limits. ",
    "applications": [
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Grease rated for deep-groove motor duty is not automatically right at 8,300 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 35.5/23 kN ratings and 1.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7208B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7208B?",
        "a": "7208B is a single-row angular contact ball bearing to ISO 15: 40 mm bore, 80 mm outside diameter, 18 mm width (1.575 x 3.15 x 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 35.5 kN, C0 23 kN and a 1.8 kN fatigue load limit Pu; the grease limiting speed is 8,300 r/min and the oil rating 11,000 r/min; mass about 375 g."
      },
      {
        "q": "How is the 7208B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 08 encodes the 40 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 80 mm OD and 18 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7208B support?",
        "a": "One 7208B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7208B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 8,300 r/min and the oil rating 11,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7208B?",
        "a": "The 40/80/18 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 35.5 kN / C0 23 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7208B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7208b",
      "7208B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ208",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ208",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 49,
    "static_load_kN": 70.5,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 3.05,
    "limiting_speed_rpm": 6900,
    "max_rpm": 6900,
    "speed_oil_rpm": 9200,
    "weight_g": 450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 40 x 80 x 18 mm, NTN QJ208 sits in the medium-duty QJ200 four-point family of the angular-contact programme. NTN builds the number from QJ2 is the four-point dimension series (medium-duty QJ200 four-point family), then the last two digits 08 give the bore by the standard code table (40 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. NTN prints 49 kN dynamic and 70.5 kN static for this size and a 3.05 kN fatigue load limit Pu. For a 40 mm shaft with combined load, the practical shortlist is this series, its neighbouring dimension series, and — where thrust reverses — a back-to-back pair rather than a single row. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "On a 40 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 6,900 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single QJ208 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 49/70.5 kN ratings and 3.05 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ208; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ208?",
        "a": "QJ208 is a four-point contact ball bearing to ISO 15: 40 mm bore, 80 mm outside diameter, 18 mm width (1.575 x 3.15 x 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 49 kN, C0 70.5 kN and a 3.05 kN fatigue load limit Pu; the grease limiting speed is 6,900 r/min and the oil rating 9,200 r/min; mass about 450 g."
      },
      {
        "q": "How is the QJ208 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 08 give the bore by the standard code table (40 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 80 mm OD and 18 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ208 support?",
        "a": "QJ208 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ208?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,900 r/min and the oil rating 9,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ208?",
        "a": "The 40/80/18 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 49 kN / C0 70.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ208",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj208",
      "QJ208"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5308S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5308S",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 90,
    "B_mm": 36.5,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 56.5,
    "static_load_kN": 41,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.5,
    "limiting_speed_rpm": 5300,
    "max_rpm": 5300,
    "speed_oil_rpm": 6700,
    "weight_g": 1030,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "5308S is an NTN double-row angular contact ball bearing: heavy-duty 5300S double-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 40 x 90 x 36.5 mm. Decoding 5308S: 53 is the double-row dimension series (heavy-duty 5300S double-row family), with 08 encodes the 40 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. Catalogue dynamic rating C is 56.5 kN against C0 41 kN — a C0/C ratio of 0.73 that is typical of an angular-contact contact ellipse. Choose the heavy-duty 5300S double-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Heat-mounting to 80-90 deg C is the clean route onto a 40 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "A 5308S mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "A 5308S mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 56.5/41 kN ratings and 2.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5308S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5308S?",
        "a": "5308S is a double-row angular contact ball bearing to ISO 15: 40 mm bore, 90 mm outside diameter, 36.5 mm width (1.575 x 3.543 x 1.437 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 56.5 kN, C0 41 kN and a 2.5 kN fatigue load limit Pu; the grease limiting speed is 5,300 r/min and the oil rating 6,700 r/min; mass about 1030 g."
      },
      {
        "q": "How is the 5308S designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 08 encodes the 40 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 90 mm OD and 36.5 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5308S support?",
        "a": "5308S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5308S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,300 r/min and the oil rating 6,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5308S?",
        "a": "The 40/90/36.5 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 56.5 kN / C0 41 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5308S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5308s",
      "5308S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5308SCLLD",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5308SCLLD",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 90,
    "B_mm": 36.5,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 49.5,
    "static_load_kN": 38,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.3,
    "limiting_speed_rpm": 4500,
    "max_rpm": 4500,
    "weight_g": 1040,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty 5300S double-row family, 5308SCLLD measures 40 mm across the bore, 90 mm over the outer ring and 36.5 mm across the faces. The designation breaks down as 53 is the double-row dimension series (heavy-duty 5300S double-row family); 08 encodes the 40 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The built-in back-to-back contact lines give the double-row bearing its two-direction thrust and moment capacity from one ring set. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed LLD contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "Do not pair two random 5308SCLLD bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "A 5308SCLLD mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 49.5/38 kN ratings and 2.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5308SCLLD; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5308SCLLD?",
        "a": "5308SCLLD is a sealed double-row angular contact ball bearing to ISO 15: 40 mm bore, 90 mm outside diameter, 36.5 mm width (1.575 x 3.543 x 1.437 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 49.5 kN, C0 38 kN and a 2.3 kN fatigue load limit Pu; the grease limiting speed is 4,500 r/min and no oil rating is printed for this execution; mass about 1040 g."
      },
      {
        "q": "How is the 5308SCLLD designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 08 encodes the 40 mm bore (bore code x 5), and CLLD marks the SC internal design with contact rubber seals on both sides. The 90 mm OD and 36.5 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5308SCLLD support?",
        "a": "5308SCLLD is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with contact rubber seals (grease-lubricated, no oil speed rating)."
      },
      {
        "q": "What lubrication speeds does NTN print for 5308SCLLD?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,500 r/min and no oil rating is printed for this execution. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5308SCLLD?",
        "a": "The 40/90/36.5 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 49.5 kN / C0 38 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5308SCLLD",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5308sclld",
      "5308SCLLD"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5308SCLLM",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5308SCLLM",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 90,
    "B_mm": 36.5,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 49.5,
    "static_load_kN": 38,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.3,
    "limiting_speed_rpm": 5300,
    "max_rpm": 5300,
    "speed_oil_rpm": 6700,
    "weight_g": 1040,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5308SCLLM appears as a heavy-duty 5300S double-row family bearing of 40 mm bore, 90 mm outside diameter and 36.5 mm width. NTN builds the number from 53 is the double-row dimension series (heavy-duty 5300S double-row family), then 08 encodes the 40 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. Catalogue mass is about 1040 g, which at this 25.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed LLM non-contact-seal executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "Grease rated for deep-groove motor duty is not automatically right at 5,300 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Grease rated for deep-groove motor duty is not automatically right at 5,300 r/min with preload; check the grease speed factor against the catalogue figure.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 49.5/38 kN ratings and 2.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5308SCLLM; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5308SCLLM?",
        "a": "5308SCLLM is a sealed double-row angular contact ball bearing to ISO 15: 40 mm bore, 90 mm outside diameter, 36.5 mm width (1.575 x 3.543 x 1.437 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 49.5 kN, C0 38 kN and a 2.3 kN fatigue load limit Pu; the grease limiting speed is 5,300 r/min and the oil rating 6,700 r/min; mass about 1040 g."
      },
      {
        "q": "How is the 5308SCLLM designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 08 encodes the 40 mm bore (bore code x 5), and CLLM marks the SC internal design with non-contact rubber seals on both sides. The 90 mm OD and 36.5 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5308SCLLM support?",
        "a": "5308SCLLM is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with non-contact rubber seals that keep the shield-level speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5308SCLLM?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,300 r/min and the oil rating 6,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5308SCLLM?",
        "a": "The 40/90/36.5 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 49.5 kN / C0 38 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5308SCLLM",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5308scllm",
      "5308SCLLM"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5308SCZZ",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5308SCZZ",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 90,
    "B_mm": 36.5,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 49.5,
    "static_load_kN": 38,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.3,
    "limiting_speed_rpm": 5300,
    "max_rpm": 5300,
    "speed_oil_rpm": 6700,
    "weight_g": 1040,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 5308SCZZ belongs to the heavy-duty 5300S double-row family: the catalogue boundary dimensions read 40 / 90 / 36.5 mm (bore / OD / width). Reading the code: 53 is the double-row dimension series (heavy-duty 5300S double-row family), 08 encodes the 40 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The static margin, C0 38 kN versus C 49.5 kN, is what supports slow oscillating duty and shock without immediate brinelling. Against a deep-groove bearing of the same 40 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Heat-mounting to 80-90 deg C is the clean route onto a 40 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "Sealed ZZ shielded executions are grease-for-life: there is no relubrication path, so the grease life calculation replaces the relubrication plan.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5308SCZZ without re-checking axial float, heat and housing width — the kinematics differ.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Do not pair two random 5308SCZZ bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 49.5/38 kN ratings and 2.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5308SCZZ; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5308SCZZ?",
        "a": "5308SCZZ is a sealed double-row angular contact ball bearing to ISO 15: 40 mm bore, 90 mm outside diameter, 36.5 mm width (1.575 x 3.543 x 1.437 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 49.5 kN, C0 38 kN and a 2.3 kN fatigue load limit Pu; the grease limiting speed is 5,300 r/min and the oil rating 6,700 r/min; mass about 1040 g."
      },
      {
        "q": "How is the 5308SCZZ designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 08 encodes the 40 mm bore (bore code x 5), and CZZ marks the double-row SC internal design with pressed-steel shields on both sides. The 90 mm OD and 36.5 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5308SCZZ support?",
        "a": "5308SCZZ is a sealed double-row bearing: thrust in both directions, radial and moment load in one envelope, with pressed-steel shields that keep the open-bearing speed ratings."
      },
      {
        "q": "What lubrication speeds does NTN print for 5308SCZZ?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,300 r/min and the oil rating 6,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5308SCZZ?",
        "a": "The 40/90/36.5 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 49.5 kN / C0 38 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5308SCZZ",
        "equiv_brand": "ISO 15",
        "level": "verify",
        "note": "ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=136",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5308sczz",
      "5308SCZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7308-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7308",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 90,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 54,
    "static_load_kN": 33,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.58,
    "limiting_speed_rpm": 8600,
    "max_rpm": 8600,
    "speed_oil_rpm": 12000,
    "weight_g": 625,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty 7300 single-row family, 7308 measures 40 mm across the bore, 90 mm over the outer ring and 23 mm across the faces. Reading the code: 73 is the single-row dimension series (heavy-duty 7300 single-row family), 08 encodes the 40 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. With C 54 kN and C0 33 kN, each mm of bore carries about 1.35 kN of dynamic rating. Size selection is usually finished by checking that the C0 of 33 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The C0 of 33 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7308 without re-checking axial float, heat and housing width — the kinematics differ.",
      "On a 40 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 54/33 kN ratings and 2.58 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7308; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7308?",
        "a": "7308 is a single-row angular contact ball bearing to ISO 15: 40 mm bore, 90 mm outside diameter, 23 mm width (1.575 x 3.543 x 0.906 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 54 kN, C0 33 kN and a 2.58 kN fatigue load limit Pu; the grease limiting speed is 8,600 r/min and the oil rating 12,000 r/min; mass about 625 g."
      },
      {
        "q": "How is the 7308 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 08 encodes the 40 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 90 mm OD and 23 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7308 support?",
        "a": "One 7308 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7308?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 8,600 r/min and the oil rating 12,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7308?",
        "a": "The 40/90/23 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 54 kN / C0 33 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7308",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7308-ACCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7308-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7308-BECBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7308-BECBP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7308-BECBY",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7308-BEGAPH",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7308-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7308",
      "7308-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7308B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7308B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 90,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 49.5,
    "static_load_kN": 30.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.37,
    "limiting_speed_rpm": 7400,
    "max_rpm": 7400,
    "speed_oil_rpm": 9900,
    "weight_g": 636,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 40 x 90 x 23 mm, NTN 7308B sits in the heavy-duty 7300 single-row family of the angular-contact programme. Two fields make up the code — 73 is the single-row dimension series (heavy-duty 7300 single-row family) and 08 encodes the 40 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). With C 49.5 kN and C0 30.5 kN, each mm of bore carries about 1.24 kN of dynamic rating. Size selection is usually finished by checking that the C0 of 30.5 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 40 mm bore give the working limits. ",
    "applications": [
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "On a 40 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Do not pair two random 7308B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "On a 40 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 49.5/30.5 kN ratings and 2.37 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7308B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7308B?",
        "a": "7308B is a single-row angular contact ball bearing to ISO 15: 40 mm bore, 90 mm outside diameter, 23 mm width (1.575 x 3.543 x 0.906 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 49.5 kN, C0 30.5 kN and a 2.37 kN fatigue load limit Pu; the grease limiting speed is 7,400 r/min and the oil rating 9,900 r/min; mass about 636 g."
      },
      {
        "q": "How is the 7308B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 08 encodes the 40 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 90 mm OD and 23 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7308B support?",
        "a": "One 7308B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7308B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,400 r/min and the oil rating 9,900 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7308B?",
        "a": "The 40/90/23 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 49.5 kN / C0 30.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7308B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7308b",
      "7308B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ308",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ308",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 40,
    "D_mm": 90,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 67,
    "static_load_kN": 91.5,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 3.95,
    "limiting_speed_rpm": 6200,
    "max_rpm": 6200,
    "speed_oil_rpm": 8200,
    "weight_g": 780,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty QJ300 four-point family, QJ308 measures 40 mm across the bore, 90 mm over the outer ring and 23 mm across the faces. Decoding QJ308: QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family), with the last two digits 08 give the bore by the standard code table (40 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The radial section height here is 25.0 mm, and the catalogue couples that with C 67 kN / C0 91.5 kN. Size selection is usually finished by checking that the C0 of 91.5 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 40 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 67/91.5 kN ratings and 3.95 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ308; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ308?",
        "a": "QJ308 is a four-point contact ball bearing to ISO 15: 40 mm bore, 90 mm outside diameter, 23 mm width (1.575 x 3.543 x 0.906 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 67 kN, C0 91.5 kN and a 3.95 kN fatigue load limit Pu; the grease limiting speed is 6,200 r/min and the oil rating 8,200 r/min; mass about 780 g."
      },
      {
        "q": "How is the QJ308 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 08 give the bore by the standard code table (40 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 90 mm OD and 23 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ308 support?",
        "a": "QJ308 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ308?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,200 r/min and the oil rating 8,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ308?",
        "a": "The 40/90/23 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 67 kN / C0 91.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ308",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj308",
      "QJ308"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7909",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7909",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 45,
    "D_mm": 68,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 17.4,
    "static_load_kN": 12.9,
    "cage_type": "polymer_PA66",
    "fatigue_load_limit_kN": 0.9,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "speed_oil_rpm": 14000,
    "weight_g": 150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7909 appears as a extra-light, high-speed 7900 single-row family bearing of 45 mm bore, 68 mm outside diameter and 12 mm width. The designation breaks down as 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 09 encodes the 45 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The oil rating of 14,000 r/min sits 4,000 r/min above the 10,000 r/min grease figure — a 1.40x step that says how much headroom oil cooling buys. The 45/68/12 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 45 mm bore give the working limits. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 45 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 12.9 kN really covers the worst static case before substituting it for a 7000.",
      "A 7909 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Grease rated for deep-groove motor duty is not automatically right at 10,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Grease rated for deep-groove motor duty is not automatically right at 10,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 17.4/12.9 kN ratings and 0.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7909; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7909?",
        "a": "7909 is a single-row angular contact ball bearing to ISO 15: 45 mm bore, 68 mm outside diameter, 12 mm width (1.772 x 2.677 x 0.472 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 17.4 kN, C0 12.9 kN and a 0.9 kN fatigue load limit Pu; the grease limiting speed is 10,000 r/min and the oil rating 14,000 r/min; mass about 150 g."
      },
      {
        "q": "How is the 7909 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 09 encodes the 45 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 68 mm OD and 12 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7909 support?",
        "a": "One 7909 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7909?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 10,000 r/min and the oil rating 14,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7909?",
        "a": "The 45/68/12 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 17.4 kN / C0 12.9 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7909",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7909"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7009-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7009",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 45,
    "D_mm": 75,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 24.7,
    "static_load_kN": 17.7,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.29,
    "limiting_speed_rpm": 9500,
    "max_rpm": 9500,
    "speed_oil_rpm": 13000,
    "weight_g": 282,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the standard-section 7000 single-row family, 7009 measures 45 mm across the bore, 75 mm over the outer ring and 16 mm across the faces. Reading the code: 70 is the single-row dimension series (standard-section 7000 single-row family), 09 encodes the 45 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The oil rating of 13,000 r/min sits 3,500 r/min above the 9,500 r/min grease figure — a 1.37x step that says how much headroom oil cooling buys. Against a deep-groove bearing of the same 45 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. A 45 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 45 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7009 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Grease rated for deep-groove motor duty is not automatically right at 9,500 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 24.7/17.7 kN ratings and 1.29 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7009; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7009?",
        "a": "7009 is a single-row angular contact ball bearing to ISO 15: 45 mm bore, 75 mm outside diameter, 16 mm width (1.772 x 2.953 x 0.63 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 24.7 kN, C0 17.7 kN and a 1.29 kN fatigue load limit Pu; the grease limiting speed is 9,500 r/min and the oil rating 13,000 r/min; mass about 282 g."
      },
      {
        "q": "How is the 7009 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 09 encodes the 45 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 75 mm OD and 16 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7009 support?",
        "a": "One 7009 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7009?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 9,500 r/min and the oil rating 13,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7009?",
        "a": "The 45/75/16 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 24.7 kN / C0 17.7 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7009",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7009",
      "7009-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5209S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5209S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 45,
    "D_mm": 85,
    "B_mm": 30.2,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 49.5,
    "static_load_kN": 38,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.3,
    "limiting_speed_rpm": 5000,
    "max_rpm": 5000,
    "speed_oil_rpm": 6700,
    "weight_g": 670,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "5209S is the 45 mm bore member of NTN's medium-duty 5200S double-row family, with a 85 mm outside diameter and 30.2 mm section width. Two fields make up the code — 52 is the double-row dimension series (medium-duty 5200S double-row family) and 09 encodes the 45 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. Catalogue mass is about 670 g, which at this 20.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Size selection is usually finished by checking that the C0 of 38 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 45 mm bore give the working limits. ",
    "applications": [
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 45 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "The C0 of 38 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 49.5/38 kN ratings and 2.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5209S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5209S?",
        "a": "5209S is a double-row angular contact ball bearing to ISO 15: 45 mm bore, 85 mm outside diameter, 30.2 mm width (1.772 x 3.346 x 1.189 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 49.5 kN, C0 38 kN and a 2.3 kN fatigue load limit Pu; the grease limiting speed is 5,000 r/min and the oil rating 6,700 r/min; mass about 670 g."
      },
      {
        "q": "How is the 5209S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 09 encodes the 45 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 85 mm OD and 30.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5209S support?",
        "a": "5209S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5209S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,000 r/min and the oil rating 6,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5209S?",
        "a": "The 45/85/30.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 49.5 kN / C0 38 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5209S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5209s",
      "5209S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7209-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7209",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 45,
    "D_mm": 85,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 44,
    "static_load_kN": 28.7,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.25,
    "limiting_speed_rpm": 8700,
    "max_rpm": 8700,
    "speed_oil_rpm": 12000,
    "weight_g": 404,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 7200 single-row family, 7209 measures 45 mm across the bore, 85 mm over the outer ring and 19 mm across the faces. NTN builds the number from 72 is the single-row dimension series (medium-duty 7200 single-row family), then 09 encodes the 45 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue dynamic rating C is 44 kN against C0 28.7 kN — a C0/C ratio of 0.65 that is typical of an angular-contact contact ellipse. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 45 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Grease rated for deep-groove motor duty is not automatically right at 8,700 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 8,700 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 44/28.7 kN ratings and 2.25 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7209; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7209?",
        "a": "7209 is a single-row angular contact ball bearing to ISO 15: 45 mm bore, 85 mm outside diameter, 19 mm width (1.772 x 3.346 x 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 44 kN, C0 28.7 kN and a 2.25 kN fatigue load limit Pu; the grease limiting speed is 8,700 r/min and the oil rating 12,000 r/min; mass about 404 g."
      },
      {
        "q": "How is the 7209 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 09 encodes the 45 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 85 mm OD and 19 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7209 support?",
        "a": "One 7209 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7209?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 8,700 r/min and the oil rating 12,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7209?",
        "a": "The 45/85/19 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 44 kN / C0 28.7 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7209",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7209-ACCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7209-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7209-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7209-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7209-BECBY",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7209-BEGAPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7209",
      "7209-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7209B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7209B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 45,
    "D_mm": 85,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 40,
    "static_load_kN": 26.2,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.04,
    "limiting_speed_rpm": 7400,
    "max_rpm": 7400,
    "speed_oil_rpm": 9900,
    "weight_g": 410,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7209B belongs to the medium-duty 7200 single-row family: the catalogue boundary dimensions read 45 / 85 / 19 mm (bore / OD / width). Reading the code: 72 is the single-row dimension series (medium-duty 7200 single-row family), 09 encodes the 45 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). At roughly 20.0 mm of radial section, the catalogue still quotes 40 kN dynamic capacity for the 45 mm bore. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 45 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Do not pair two random 7209B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 7,400 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 40/26.2 kN ratings and 2.04 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7209B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7209B?",
        "a": "7209B is a single-row angular contact ball bearing to ISO 15: 45 mm bore, 85 mm outside diameter, 19 mm width (1.772 x 3.346 x 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 40 kN, C0 26.2 kN and a 2.04 kN fatigue load limit Pu; the grease limiting speed is 7,400 r/min and the oil rating 9,900 r/min; mass about 410 g."
      },
      {
        "q": "How is the 7209B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 09 encodes the 45 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 85 mm OD and 19 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7209B support?",
        "a": "One 7209B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7209B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,400 r/min and the oil rating 9,900 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7209B?",
        "a": "The 45/85/19 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 40 kN / C0 26.2 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7209B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7209b",
      "7209B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ209",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ209",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 45,
    "D_mm": 85,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 55,
    "static_load_kN": 81,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 3.5,
    "limiting_speed_rpm": 6200,
    "max_rpm": 6200,
    "speed_oil_rpm": 8200,
    "weight_g": 520,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "QJ209 is the 45 mm bore member of NTN's medium-duty QJ200 four-point family, with a 85 mm outside diameter and 19 mm section width. The designation breaks down as QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 09 give the bore by the standard code table (45 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Against a deep-groove bearing of the same 45 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Grease quantity matters as much as grade at 6,200 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 45 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single QJ209 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 6,200 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 55/81 kN ratings and 3.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ209; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ209?",
        "a": "QJ209 is a four-point contact ball bearing to ISO 15: 45 mm bore, 85 mm outside diameter, 19 mm width (1.772 x 3.346 x 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 55 kN, C0 81 kN and a 3.5 kN fatigue load limit Pu; the grease limiting speed is 6,200 r/min and the oil rating 8,200 r/min; mass about 520 g."
      },
      {
        "q": "How is the QJ209 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 09 give the bore by the standard code table (45 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 85 mm OD and 19 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ209 support?",
        "a": "QJ209 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ209?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,200 r/min and the oil rating 8,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ209?",
        "a": "The 45/85/19 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 55 kN / C0 81 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ209",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj209",
      "QJ209"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5309S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5309S",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 45,
    "D_mm": 100,
    "B_mm": 39.7,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 68.5,
    "static_load_kN": 51,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 3.1,
    "limiting_speed_rpm": 4500,
    "max_rpm": 4500,
    "speed_oil_rpm": 6000,
    "weight_g": 1370,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The heavy-duty 5300S double-row family entry 5309S carries a 45 mm bore in a 100 mm outside diameter, 39.7 mm wide envelope. The designation breaks down as 53 is the double-row dimension series (heavy-duty 5300S double-row family); 09 encodes the 45 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. NTN prints 68.5 kN dynamic and 51 kN static for this size and a 3.1 kN fatigue load limit Pu. Against a deep-groove bearing of the same 45 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 45 mm bore give the working limits. ",
    "applications": [
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 45 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Do not pair two random 5309S bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5309S without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 68.5/51 kN ratings and 3.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5309S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5309S?",
        "a": "5309S is a double-row angular contact ball bearing to ISO 15: 45 mm bore, 100 mm outside diameter, 39.7 mm width (1.772 x 3.937 x 1.563 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 68.5 kN, C0 51 kN and a 3.1 kN fatigue load limit Pu; the grease limiting speed is 4,500 r/min and the oil rating 6,000 r/min; mass about 1370 g."
      },
      {
        "q": "How is the 5309S designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 09 encodes the 45 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 100 mm OD and 39.7 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5309S support?",
        "a": "5309S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5309S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,500 r/min and the oil rating 6,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5309S?",
        "a": "The 45/100/39.7 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 68.5 kN / C0 51 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5309S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5309s",
      "5309S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7309-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7309",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 45,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 70.5,
    "static_load_kN": 44,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 3.45,
    "limiting_speed_rpm": 7800,
    "max_rpm": 7800,
    "speed_oil_rpm": 10000,
    "weight_g": 837,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7309 is an NTN single-row angular contact ball bearing: heavy-duty 7300 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 45 x 100 x 25 mm. Decoding 7309: 73 is the single-row dimension series (heavy-duty 7300 single-row family), with 09 encodes the 45 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The static margin, C0 44 kN versus C 70.5 kN, is what supports slow oscillating duty and shock without immediate brinelling. The 45/100/25 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 45 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The 7,800 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Do not pair two random 7309 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 70.5/44 kN ratings and 3.45 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7309; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7309?",
        "a": "7309 is a single-row angular contact ball bearing to ISO 15: 45 mm bore, 100 mm outside diameter, 25 mm width (1.772 x 3.937 x 0.984 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 70.5 kN, C0 44 kN and a 3.45 kN fatigue load limit Pu; the grease limiting speed is 7,800 r/min and the oil rating 10,000 r/min; mass about 837 g."
      },
      {
        "q": "How is the 7309 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 09 encodes the 45 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 100 mm OD and 25 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7309 support?",
        "a": "One 7309 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7309?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,800 r/min and the oil rating 10,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7309?",
        "a": "The 45/100/25 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 70.5 kN / C0 44 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7309",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7309-ACCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7309-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7309-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7309-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7309-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7309-BEGAPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7309-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7309",
      "7309-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7309B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7309B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 45,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 64.5,
    "static_load_kN": 40.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 3.15,
    "limiting_speed_rpm": 6600,
    "max_rpm": 6600,
    "speed_oil_rpm": 8900,
    "weight_g": 854,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7309B is an NTN single-row angular contact ball bearing: heavy-duty 7300 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 45 x 100 x 25 mm. NTN builds the number from 73 is the single-row dimension series (heavy-duty 7300 single-row family), then 09 encodes the 45 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The oil rating of 8,900 r/min sits 2,300 r/min above the 6,600 r/min grease figure — a 1.35x step that says how much headroom oil cooling buys. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 45 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "A 7309B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Grease rated for deep-groove motor duty is not automatically right at 6,600 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 64.5/40.5 kN ratings and 3.15 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7309B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7309B?",
        "a": "7309B is a single-row angular contact ball bearing to ISO 15: 45 mm bore, 100 mm outside diameter, 25 mm width (1.772 x 3.937 x 0.984 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 64.5 kN, C0 40.5 kN and a 3.15 kN fatigue load limit Pu; the grease limiting speed is 6,600 r/min and the oil rating 8,900 r/min; mass about 854 g."
      },
      {
        "q": "How is the 7309B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 09 encodes the 45 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 100 mm OD and 25 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7309B support?",
        "a": "One 7309B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7309B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,600 r/min and the oil rating 8,900 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7309B?",
        "a": "The 45/100/25 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 64.5 kN / C0 40.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7309B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7309b",
      "7309B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ309",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ309",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 45,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 87,
    "static_load_kN": 121,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 5.2,
    "limiting_speed_rpm": 5500,
    "max_rpm": 5500,
    "speed_oil_rpm": 7400,
    "weight_g": 1050,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "QJ309 is an NTN four-point contact ball bearing: heavy-duty QJ300 four-point family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 45 x 100 x 25 mm. NTN builds the number from QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family), then the last two digits 09 give the bore by the standard code table (45 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 35 deg four-point geometry doubles the axial contact points, so the 87 kN rating is available for thrust in both directions. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Grease quantity matters as much as grade at 5,500 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 45 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "On a 45 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "A QJ309 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 87/121 kN ratings and 5.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ309; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ309?",
        "a": "QJ309 is a four-point contact ball bearing to ISO 15: 45 mm bore, 100 mm outside diameter, 25 mm width (1.772 x 3.937 x 0.984 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 87 kN, C0 121 kN and a 5.2 kN fatigue load limit Pu; the grease limiting speed is 5,500 r/min and the oil rating 7,400 r/min; mass about 1050 g."
      },
      {
        "q": "How is the QJ309 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 09 give the bore by the standard code table (45 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 100 mm OD and 25 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ309 support?",
        "a": "QJ309 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ309?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,500 r/min and the oil rating 7,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ309?",
        "a": "The 45/100/25 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 87 kN / C0 121 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ309",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj309",
      "QJ309"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7910",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7910",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 50,
    "D_mm": 72,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 18.4,
    "static_load_kN": 14.5,
    "cage_type": "polymer_PA66",
    "fatigue_load_limit_kN": 0.98,
    "limiting_speed_rpm": 9200,
    "max_rpm": 9200,
    "speed_oil_rpm": 12000,
    "weight_g": 157,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7910 belongs to the extra-light, high-speed 7900 single-row family: the catalogue boundary dimensions read 50 / 72 / 12 mm (bore / OD / width). Decoding 7910: 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), with 10 encodes the 50 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Size selection is usually finished by checking that the C0 of 14.5 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 50 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 14.5 kN really covers the worst static case before substituting it for a 7000.",
      "The 9,200 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The C0 of 14.5 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 9,200 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 18.4/14.5 kN ratings and 0.98 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7910; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7910?",
        "a": "7910 is a single-row angular contact ball bearing to ISO 15: 50 mm bore, 72 mm outside diameter, 12 mm width (1.969 x 2.835 x 0.472 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 18.4 kN, C0 14.5 kN and a 0.98 kN fatigue load limit Pu; the grease limiting speed is 9,200 r/min and the oil rating 12,000 r/min; mass about 157 g."
      },
      {
        "q": "How is the 7910 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 10 encodes the 50 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 72 mm OD and 12 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7910 support?",
        "a": "One 7910 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7910?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 9,200 r/min and the oil rating 12,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7910?",
        "a": "The 50/72/12 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 18.4 kN / C0 14.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7910",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7910"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7010-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7010",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 50,
    "D_mm": 80,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 26.2,
    "static_load_kN": 20.1,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.42,
    "limiting_speed_rpm": 8600,
    "max_rpm": 8600,
    "speed_oil_rpm": 11000,
    "weight_g": 306,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The standard-section 7000 single-row family entry 7010 carries a 50 mm bore in a 80 mm outside diameter, 16 mm wide envelope. The designation breaks down as 70 is the single-row dimension series (standard-section 7000 single-row family); 10 encodes the 50 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue dynamic rating C is 26.2 kN against C0 20.1 kN — a C0/C ratio of 0.77 that is typical of an angular-contact contact ellipse. Size selection is usually finished by checking that the C0 of 20.1 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 50 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A 7010 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The C0 of 20.1 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 26.2/20.1 kN ratings and 1.42 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7010; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7010?",
        "a": "7010 is a single-row angular contact ball bearing to ISO 15: 50 mm bore, 80 mm outside diameter, 16 mm width (1.969 x 3.15 x 0.63 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 26.2 kN, C0 20.1 kN and a 1.42 kN fatigue load limit Pu; the grease limiting speed is 8,600 r/min and the oil rating 11,000 r/min; mass about 306 g."
      },
      {
        "q": "How is the 7010 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 10 encodes the 50 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 80 mm OD and 16 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7010 support?",
        "a": "One 7010 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7010?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 8,600 r/min and the oil rating 11,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7010?",
        "a": "The 50/80/16 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 26.2 kN / C0 20.1 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7010",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7010",
      "7010-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5210S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5210S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 50,
    "D_mm": 90,
    "B_mm": 30.2,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 53,
    "static_load_kN": 43.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.7,
    "limiting_speed_rpm": 4800,
    "max_rpm": 4800,
    "speed_oil_rpm": 6000,
    "weight_g": 720,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5210S appears as a medium-duty 5200S double-row family bearing of 50 mm bore, 90 mm outside diameter and 30.2 mm width. Decoding 5210S: 52 is the double-row dimension series (medium-duty 5200S double-row family), with 10 encodes the 50 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. Catalogue dynamic rating C is 53 kN against C0 43.5 kN — a C0/C ratio of 0.82 that is typical of an angular-contact contact ellipse. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 50 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "A 5210S mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 4,800 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 53/43.5 kN ratings and 2.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5210S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5210S?",
        "a": "5210S is a double-row angular contact ball bearing to ISO 15: 50 mm bore, 90 mm outside diameter, 30.2 mm width (1.969 x 3.543 x 1.189 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 53 kN, C0 43.5 kN and a 2.7 kN fatigue load limit Pu; the grease limiting speed is 4,800 r/min and the oil rating 6,000 r/min; mass about 720 g."
      },
      {
        "q": "How is the 5210S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 10 encodes the 50 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 90 mm OD and 30.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5210S support?",
        "a": "5210S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5210S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,800 r/min and the oil rating 6,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5210S?",
        "a": "The 50/90/30.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 53 kN / C0 43.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5210S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5210s",
      "5210S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7210-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7210",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 50,
    "D_mm": 90,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 45.5,
    "static_load_kN": 31.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.46,
    "limiting_speed_rpm": 7900,
    "max_rpm": 7900,
    "speed_oil_rpm": 10000,
    "weight_g": 457,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 7200 single-row family entry 7210 carries a 50 mm bore in a 90 mm outside diameter, 20 mm wide envelope. Decoding 7210: 72 is the single-row dimension series (medium-duty 7200 single-row family), with 10 encodes the 50 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. At roughly 20.0 mm of radial section, the catalogue still quotes 45.5 kN dynamic capacity for the 50 mm bore. Against a deep-groove bearing of the same 50 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Grease quantity matters as much as grade at 7,900 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 50 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The 7,900 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Do not pair two random 7210 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 45.5/31.5 kN ratings and 2.46 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7210; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7210?",
        "a": "7210 is a single-row angular contact ball bearing to ISO 15: 50 mm bore, 90 mm outside diameter, 20 mm width (1.969 x 3.543 x 0.787 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 45.5 kN, C0 31.5 kN and a 2.46 kN fatigue load limit Pu; the grease limiting speed is 7,900 r/min and the oil rating 10,000 r/min; mass about 457 g."
      },
      {
        "q": "How is the 7210 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 10 encodes the 50 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 90 mm OD and 20 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7210 support?",
        "a": "One 7210 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7210?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,900 r/min and the oil rating 10,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7210?",
        "a": "The 50/90/20 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 45.5 kN / C0 31.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7210",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7210-ACCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7210-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7210-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7210-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7210-BECBPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7210-BECBY",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7210-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7210",
      "7210-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7210B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7210B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 50,
    "D_mm": 90,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 41.5,
    "static_load_kN": 28.6,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.16,
    "limiting_speed_rpm": 6700,
    "max_rpm": 6700,
    "speed_oil_rpm": 9000,
    "weight_g": 466,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7210B is the 50 mm bore member of NTN's medium-duty 7200 single-row family, with a 90 mm outside diameter and 20 mm section width. The designation breaks down as 72 is the single-row dimension series (medium-duty 7200 single-row family); 10 encodes the 50 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). With C 41.5 kN and C0 28.6 kN, each mm of bore carries about 0.83 kN of dynamic rating. Size selection is usually finished by checking that the C0 of 28.6 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Heat-mounting to 80-90 deg C is the clean route onto a 50 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 50 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "A 7210B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "On a 50 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 41.5/28.6 kN ratings and 2.16 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7210B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7210B?",
        "a": "7210B is a single-row angular contact ball bearing to ISO 15: 50 mm bore, 90 mm outside diameter, 20 mm width (1.969 x 3.543 x 0.787 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 41.5 kN, C0 28.6 kN and a 2.16 kN fatigue load limit Pu; the grease limiting speed is 6,700 r/min and the oil rating 9,000 r/min; mass about 466 g."
      },
      {
        "q": "How is the 7210B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 10 encodes the 50 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 90 mm OD and 20 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7210B support?",
        "a": "One 7210B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7210B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,700 r/min and the oil rating 9,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7210B?",
        "a": "The 50/90/20 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 41.5 kN / C0 28.6 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7210B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7210b",
      "7210B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ210",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ210",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 50,
    "D_mm": 90,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 57.5,
    "static_load_kN": 89,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 3.8,
    "limiting_speed_rpm": 5600,
    "max_rpm": 5600,
    "speed_oil_rpm": 7500,
    "weight_g": 603,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty QJ200 four-point family, QJ210 measures 50 mm across the bore, 90 mm over the outer ring and 20 mm across the faces. Decoding QJ210: QJ2 is the four-point dimension series (medium-duty QJ200 four-point family), with the last two digits 10 give the bore by the standard code table (50 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. On speed, the grease limiting speed is 5,600 r/min and the oil rating 7,500 r/min. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 50 mm bore give the working limits. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 50 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Grease rated for deep-groove motor duty is not automatically right at 5,600 r/min with preload; check the grease speed factor against the catalogue figure.",
      "On a 50 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The C0 of 89 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 57.5/89 kN ratings and 3.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ210; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ210?",
        "a": "QJ210 is a four-point contact ball bearing to ISO 15: 50 mm bore, 90 mm outside diameter, 20 mm width (1.969 x 3.543 x 0.787 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 57.5 kN, C0 89 kN and a 3.8 kN fatigue load limit Pu; the grease limiting speed is 5,600 r/min and the oil rating 7,500 r/min; mass about 603 g."
      },
      {
        "q": "How is the QJ210 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 10 give the bore by the standard code table (50 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 90 mm OD and 20 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ210 support?",
        "a": "QJ210 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ210?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,600 r/min and the oil rating 7,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ210?",
        "a": "The 50/90/20 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 57.5 kN / C0 89 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ210",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj210",
      "QJ210"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5310S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5310S",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 50,
    "D_mm": 110,
    "B_mm": 44.4,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 81.5,
    "static_load_kN": 61.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 3.8,
    "limiting_speed_rpm": 4300,
    "max_rpm": 4300,
    "speed_oil_rpm": 5600,
    "weight_g": 1840,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty 5300S double-row family, 5310S measures 50 mm across the bore, 110 mm over the outer ring and 44.4 mm across the faces. Reading the code: 53 is the double-row dimension series (heavy-duty 5300S double-row family), 10 encodes the 50 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. NTN prints 81.5 kN dynamic and 61.5 kN static for this size and a 3.8 kN fatigue load limit Pu. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 50 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "The 4,300 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Do not pair two random 5310S bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5310S without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 81.5/61.5 kN ratings and 3.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5310S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5310S?",
        "a": "5310S is a double-row angular contact ball bearing to ISO 15: 50 mm bore, 110 mm outside diameter, 44.4 mm width (1.969 x 4.331 x 1.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 81.5 kN, C0 61.5 kN and a 3.8 kN fatigue load limit Pu; the grease limiting speed is 4,300 r/min and the oil rating 5,600 r/min; mass about 1840 g."
      },
      {
        "q": "How is the 5310S designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 10 encodes the 50 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 110 mm OD and 44.4 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5310S support?",
        "a": "5310S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5310S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,300 r/min and the oil rating 5,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5310S?",
        "a": "The 50/110/44.4 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 81.5 kN / C0 61.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5310S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5310s",
      "5310S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7310-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7310",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 50,
    "D_mm": 110,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 82.5,
    "static_load_kN": 52.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 4.1,
    "limiting_speed_rpm": 7100,
    "max_rpm": 7100,
    "speed_oil_rpm": 9400,
    "weight_g": 1090,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 50 x 110 x 27 mm, NTN 7310 sits in the heavy-duty 7300 single-row family of the angular-contact programme. NTN builds the number from 73 is the single-row dimension series (heavy-duty 7300 single-row family), then 10 encodes the 50 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The oil rating of 9,400 r/min sits 2,300 r/min above the 7,100 r/min grease figure — a 1.32x step that says how much headroom oil cooling buys. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Grease quantity matters as much as grade at 7,100 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 50 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The 7,100 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "A 7310 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Grease rated for deep-groove motor duty is not automatically right at 7,100 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 82.5/52.5 kN ratings and 4.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7310; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7310?",
        "a": "7310 is a single-row angular contact ball bearing to ISO 15: 50 mm bore, 110 mm outside diameter, 27 mm width (1.969 x 4.331 x 1.063 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 82.5 kN, C0 52.5 kN and a 4.1 kN fatigue load limit Pu; the grease limiting speed is 7,100 r/min and the oil rating 9,400 r/min; mass about 1090 g."
      },
      {
        "q": "How is the 7310 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 10 encodes the 50 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 110 mm OD and 27 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7310 support?",
        "a": "One 7310 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7310?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,100 r/min and the oil rating 9,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7310?",
        "a": "The 50/110/27 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 82.5 kN / C0 52.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7310",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7310-ACCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7310-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7310-BECBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7310-BECBP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7310-BECBY",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7310-BEGAPH",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7310",
      "7310-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7310B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7310B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 50,
    "D_mm": 110,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 75.5,
    "static_load_kN": 48.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 3.8,
    "limiting_speed_rpm": 6000,
    "max_rpm": 6000,
    "speed_oil_rpm": 8100,
    "weight_g": 1110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The heavy-duty 7300 single-row family entry 7310B carries a 50 mm bore in a 110 mm outside diameter, 27 mm wide envelope. Decoding 7310B: 73 is the single-row dimension series (heavy-duty 7300 single-row family), with 10 encodes the 50 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The oil rating of 8,100 r/min sits 2,100 r/min above the 6,000 r/min grease figure — a 1.35x step that says how much headroom oil cooling buys. Choose the heavy-duty 7300 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. A 50 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 50 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Do not pair two random 7310B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Grease rated for deep-groove motor duty is not automatically right at 6,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 75.5/48.5 kN ratings and 3.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7310B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7310B?",
        "a": "7310B is a single-row angular contact ball bearing to ISO 15: 50 mm bore, 110 mm outside diameter, 27 mm width (1.969 x 4.331 x 1.063 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 75.5 kN, C0 48.5 kN and a 3.8 kN fatigue load limit Pu; the grease limiting speed is 6,000 r/min and the oil rating 8,100 r/min; mass about 1110 g."
      },
      {
        "q": "How is the 7310B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 10 encodes the 50 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 110 mm OD and 27 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7310B support?",
        "a": "One 7310B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7310B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,000 r/min and the oil rating 8,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7310B?",
        "a": "The 50/110/27 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 75.5 kN / C0 48.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7310B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7310b",
      "7310B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ310",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ310",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 50,
    "D_mm": 110,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 102,
    "static_load_kN": 145,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 6.2,
    "limiting_speed_rpm": 5000,
    "max_rpm": 5000,
    "speed_oil_rpm": 6700,
    "weight_g": 1380,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, QJ310 appears as a heavy-duty QJ300 four-point family bearing of 50 mm bore, 110 mm outside diameter and 27 mm width. Two fields make up the code — QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family) and the last two digits 10 give the bore by the standard code table (50 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The oil rating of 6,700 r/min sits 1,700 r/min above the 5,000 r/min grease figure — a 1.34x step that says how much headroom oil cooling buys. The 50/110/27 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 50 mm bore give the working limits. ",
    "applications": [
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 50 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single QJ310 without re-checking axial float, heat and housing width — the kinematics differ.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Grease rated for deep-groove motor duty is not automatically right at 5,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 102/145 kN ratings and 6.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ310; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ310?",
        "a": "QJ310 is a four-point contact ball bearing to ISO 15: 50 mm bore, 110 mm outside diameter, 27 mm width (1.969 x 4.331 x 1.063 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 102 kN, C0 145 kN and a 6.2 kN fatigue load limit Pu; the grease limiting speed is 5,000 r/min and the oil rating 6,700 r/min; mass about 1380 g."
      },
      {
        "q": "How is the QJ310 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 10 give the bore by the standard code table (50 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 110 mm OD and 27 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ310 support?",
        "a": "QJ310 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ310?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,000 r/min and the oil rating 6,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ310?",
        "a": "The 50/110/27 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 102 kN / C0 145 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ310",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj310",
      "QJ310"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7911",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7911",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 55,
    "D_mm": 80,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 19.2,
    "static_load_kN": 16.1,
    "cage_type": "polymer_PA66",
    "fatigue_load_limit_kN": 1.07,
    "limiting_speed_rpm": 8400,
    "max_rpm": 8400,
    "speed_oil_rpm": 11000,
    "weight_g": 214,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The extra-light, high-speed 7900 single-row family entry 7911 carries a 55 mm bore in a 80 mm outside diameter, 13 mm wide envelope. NTN builds the number from 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), then 11 encodes the 55 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue mass is about 214 g, which at this 12.5 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. A 55 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 55 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 16.1 kN really covers the worst static case before substituting it for a 7000.",
      "On a 55 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 19.2/16.1 kN ratings and 1.07 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7911; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7911?",
        "a": "7911 is a single-row angular contact ball bearing to ISO 15: 55 mm bore, 80 mm outside diameter, 13 mm width (2.165 x 3.15 x 0.512 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 19.2 kN, C0 16.1 kN and a 1.07 kN fatigue load limit Pu; the grease limiting speed is 8,400 r/min and the oil rating 11,000 r/min; mass about 214 g."
      },
      {
        "q": "How is the 7911 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 11 encodes the 55 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 80 mm OD and 13 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7911 support?",
        "a": "One 7911 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7911?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 8,400 r/min and the oil rating 11,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7911?",
        "a": "The 55/80/13 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 19.2 kN / C0 16.1 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7911",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7911"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7011-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7011",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 55,
    "D_mm": 90,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 34.5,
    "static_load_kN": 26.3,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.9,
    "limiting_speed_rpm": 7900,
    "max_rpm": 7900,
    "speed_oil_rpm": 11000,
    "weight_g": 447,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 55 x 90 x 18 mm, NTN 7011 sits in the standard-section 7000 single-row family of the angular-contact programme. Two fields make up the code — 70 is the single-row dimension series (standard-section 7000 single-row family) and 11 encodes the 55 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. At roughly 17.5 mm of radial section, the catalogue still quotes 34.5 kN dynamic capacity for the 55 mm bore. The 55/90/18 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 55 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7011 without re-checking axial float, heat and housing width — the kinematics differ.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 34.5/26.3 kN ratings and 1.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7011; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7011?",
        "a": "7011 is a single-row angular contact ball bearing to ISO 15: 55 mm bore, 90 mm outside diameter, 18 mm width (2.165 x 3.543 x 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 34.5 kN, C0 26.3 kN and a 1.9 kN fatigue load limit Pu; the grease limiting speed is 7,900 r/min and the oil rating 11,000 r/min; mass about 447 g."
      },
      {
        "q": "How is the 7011 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 11 encodes the 55 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 90 mm OD and 18 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7011 support?",
        "a": "One 7011 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7011?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,900 r/min and the oil rating 11,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7011?",
        "a": "The 55/90/18 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 34.5 kN / C0 26.3 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7011",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7011",
      "7011-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5211S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5211S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 55,
    "D_mm": 100,
    "B_mm": 33.3,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 56,
    "static_load_kN": 49,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 3,
    "limiting_speed_rpm": 4300,
    "max_rpm": 4300,
    "speed_oil_rpm": 5600,
    "weight_g": 1010,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 55 x 100 x 33.3 mm, NTN 5211S sits in the medium-duty 5200S double-row family of the angular-contact programme. The designation breaks down as 52 is the double-row dimension series (medium-duty 5200S double-row family); 11 encodes the 55 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. NTN prints 56 kN dynamic and 49 kN static for this size and a 3 kN fatigue load limit Pu. For a 55 mm shaft with combined load, the practical shortlist is this series, its neighbouring dimension series, and — where thrust reverses — a back-to-back pair rather than a single row. Heat-mounting to 80-90 deg C is the clean route onto a 55 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 55 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "A 5211S mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5211S without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 56/49 kN ratings and 3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5211S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5211S?",
        "a": "5211S is a double-row angular contact ball bearing to ISO 15: 55 mm bore, 100 mm outside diameter, 33.3 mm width (2.165 x 3.937 x 1.311 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 56 kN, C0 49 kN and a 3 kN fatigue load limit Pu; the grease limiting speed is 4,300 r/min and the oil rating 5,600 r/min; mass about 1010 g."
      },
      {
        "q": "How is the 5211S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 11 encodes the 55 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 100 mm OD and 33.3 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5211S support?",
        "a": "5211S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5211S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,300 r/min and the oil rating 5,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5211S?",
        "a": "The 55/100/33.3 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 56 kN / C0 49 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5211S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5211s",
      "5211S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7211-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7211",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 55,
    "D_mm": 100,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 56.5,
    "static_load_kN": 39.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 3.1,
    "limiting_speed_rpm": 7100,
    "max_rpm": 7100,
    "speed_oil_rpm": 9500,
    "weight_g": 600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 55 x 100 x 21 mm, NTN 7211 sits in the medium-duty 7200 single-row family of the angular-contact programme. Two fields make up the code — 72 is the single-row dimension series (medium-duty 7200 single-row family) and 11 encodes the 55 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. NTN prints 56.5 kN dynamic and 39.5 kN static for this size and a 3.1 kN fatigue load limit Pu. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Grease quantity matters as much as grade at 7,100 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 55 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A 7211 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The C0 of 39.5 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7211 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 56.5/39.5 kN ratings and 3.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7211; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7211?",
        "a": "7211 is a single-row angular contact ball bearing to ISO 15: 55 mm bore, 100 mm outside diameter, 21 mm width (2.165 x 3.937 x 0.827 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 56.5 kN, C0 39.5 kN and a 3.1 kN fatigue load limit Pu; the grease limiting speed is 7,100 r/min and the oil rating 9,500 r/min; mass about 600 g."
      },
      {
        "q": "How is the 7211 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 11 encodes the 55 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 100 mm OD and 21 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7211 support?",
        "a": "One 7211 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7211?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,100 r/min and the oil rating 9,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7211?",
        "a": "The 55/100/21 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 56.5 kN / C0 39.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7211",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7211-ACCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7211-BE-2RZP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant (OPEN vs RSR) and load ratings differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "7211-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7211-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7211-BECBPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7211-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7211-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7211",
      "7211-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7211B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7211B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 55,
    "D_mm": 100,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 51.5,
    "static_load_kN": 36,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.74,
    "limiting_speed_rpm": 6100,
    "max_rpm": 6100,
    "speed_oil_rpm": 8200,
    "weight_g": 612,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7211B appears as a medium-duty 7200 single-row family bearing of 55 mm bore, 100 mm outside diameter and 21 mm width. Two fields make up the code — 72 is the single-row dimension series (medium-duty 7200 single-row family) and 11 encodes the 55 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The oil rating of 8,200 r/min sits 2,100 r/min above the 6,100 r/min grease figure — a 1.34x step that says how much headroom oil cooling buys. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 55 mm bore give the working limits. ",
    "applications": [
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 55 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Grease rated for deep-groove motor duty is not automatically right at 6,100 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Do not pair two random 7211B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Grease rated for deep-groove motor duty is not automatically right at 6,100 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 51.5/36 kN ratings and 2.74 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7211B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7211B?",
        "a": "7211B is a single-row angular contact ball bearing to ISO 15: 55 mm bore, 100 mm outside diameter, 21 mm width (2.165 x 3.937 x 0.827 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 51.5 kN, C0 36 kN and a 2.74 kN fatigue load limit Pu; the grease limiting speed is 6,100 r/min and the oil rating 8,200 r/min; mass about 612 g."
      },
      {
        "q": "How is the 7211B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 11 encodes the 55 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 100 mm OD and 21 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7211B support?",
        "a": "One 7211B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7211B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,100 r/min and the oil rating 8,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7211B?",
        "a": "The 55/100/21 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 51.5 kN / C0 36 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7211B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7211b",
      "7211B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ211",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ211",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 55,
    "D_mm": 100,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 71,
    "static_load_kN": 112,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 4.8,
    "limiting_speed_rpm": 5100,
    "max_rpm": 5100,
    "speed_oil_rpm": 6800,
    "weight_g": 780,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "QJ211 is an NTN four-point contact ball bearing: medium-duty QJ200 four-point family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 55 x 100 x 21 mm. NTN builds the number from QJ2 is the four-point dimension series (medium-duty QJ200 four-point family), then the last two digits 11 give the bore by the standard code table (55 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. With C 71 kN and C0 112 kN, each mm of bore carries about 1.29 kN of dynamic rating. Choose the medium-duty QJ200 four-point family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Heat-mounting to 80-90 deg C is the clean route onto a 55 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 55 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "On a 55 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 71/112 kN ratings and 4.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ211; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ211?",
        "a": "QJ211 is a four-point contact ball bearing to ISO 15: 55 mm bore, 100 mm outside diameter, 21 mm width (2.165 x 3.937 x 0.827 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 71 kN, C0 112 kN and a 4.8 kN fatigue load limit Pu; the grease limiting speed is 5,100 r/min and the oil rating 6,800 r/min; mass about 780 g."
      },
      {
        "q": "How is the QJ211 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 11 give the bore by the standard code table (55 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 100 mm OD and 21 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ211 support?",
        "a": "QJ211 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ211?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,100 r/min and the oil rating 6,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ211?",
        "a": "The 55/100/21 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 71 kN / C0 112 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ211",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj211",
      "QJ211"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5311S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5311S",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 55,
    "D_mm": 120,
    "B_mm": 49.2,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 95,
    "static_load_kN": 73,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 4.5,
    "limiting_speed_rpm": 3800,
    "max_rpm": 3800,
    "speed_oil_rpm": 5000,
    "weight_g": 2400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 5311S belongs to the heavy-duty 5300S double-row family: the catalogue boundary dimensions read 55 / 120 / 49.2 mm (bore / OD / width). Decoding 5311S: 53 is the double-row dimension series (heavy-duty 5300S double-row family), with 11 encodes the 55 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. Catalogue mass is about 2400 g, which at this 32.5 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. A 55 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 55 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 95/73 kN ratings and 4.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5311S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5311S?",
        "a": "5311S is a double-row angular contact ball bearing to ISO 15: 55 mm bore, 120 mm outside diameter, 49.2 mm width (2.165 x 4.724 x 1.937 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 95 kN, C0 73 kN and a 4.5 kN fatigue load limit Pu; the grease limiting speed is 3,800 r/min and the oil rating 5,000 r/min; mass about 2400 g."
      },
      {
        "q": "How is the 5311S designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 11 encodes the 55 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 120 mm OD and 49.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5311S support?",
        "a": "5311S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5311S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,800 r/min and the oil rating 5,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5311S?",
        "a": "The 55/120/49.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 95 kN / C0 73 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5311S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5311s",
      "5311S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7311-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7311",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 55,
    "D_mm": 120,
    "B_mm": 29,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 95,
    "static_load_kN": 61.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 4.8,
    "limiting_speed_rpm": 6400,
    "max_rpm": 6400,
    "speed_oil_rpm": 8600,
    "weight_g": 1390,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7311 is the 55 mm bore member of NTN's heavy-duty 7300 single-row family, with a 120 mm outside diameter and 29 mm section width. Reading the code: 73 is the single-row dimension series (heavy-duty 7300 single-row family), 11 encodes the 55 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue dynamic rating C is 95 kN against C0 61.5 kN — a C0/C ratio of 0.65 that is typical of an angular-contact contact ellipse. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Grease quantity matters as much as grade at 6,400 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling",
      "industrial pump and blower impeller shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 55 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Grease rated for deep-groove motor duty is not automatically right at 6,400 r/min with preload; check the grease speed factor against the catalogue figure.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 95/61.5 kN ratings and 4.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7311; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7311?",
        "a": "7311 is a single-row angular contact ball bearing to ISO 15: 55 mm bore, 120 mm outside diameter, 29 mm width (2.165 x 4.724 x 1.142 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 95 kN, C0 61.5 kN and a 4.8 kN fatigue load limit Pu; the grease limiting speed is 6,400 r/min and the oil rating 8,600 r/min; mass about 1390 g."
      },
      {
        "q": "How is the 7311 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 11 encodes the 55 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 120 mm OD and 29 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7311 support?",
        "a": "One 7311 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7311?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,400 r/min and the oil rating 8,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7311?",
        "a": "The 55/120/29 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 95 kN / C0 61.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7311",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7311-ACCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7311-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7311-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7311-BECBPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7311-BECBY",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7311-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7311",
      "7311-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7311B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7311B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 55,
    "D_mm": 120,
    "B_mm": 29,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 87,
    "static_load_kN": 56.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 4.45,
    "limiting_speed_rpm": 5500,
    "max_rpm": 5500,
    "speed_oil_rpm": 7300,
    "weight_g": 1420,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty 7300 single-row family, 7311B measures 55 mm across the bore, 120 mm over the outer ring and 29 mm across the faces. The designation breaks down as 73 is the single-row dimension series (heavy-duty 7300 single-row family); 11 encodes the 55 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). At roughly 32.5 mm of radial section, the catalogue still quotes 87 kN dynamic capacity for the 55 mm bore. Against a deep-groove bearing of the same 55 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "industrial pump and blower impeller shafts",
      "gearbox input shafts under helical-gear thrust",
      "electric motor shafts with axial locating duty",
      "conveyor drive and tension-drum shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 55 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "The C0 of 56.5 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 87/56.5 kN ratings and 4.45 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7311B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7311B?",
        "a": "7311B is a single-row angular contact ball bearing to ISO 15: 55 mm bore, 120 mm outside diameter, 29 mm width (2.165 x 4.724 x 1.142 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 87 kN, C0 56.5 kN and a 4.45 kN fatigue load limit Pu; the grease limiting speed is 5,500 r/min and the oil rating 7,300 r/min; mass about 1420 g."
      },
      {
        "q": "How is the 7311B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 11 encodes the 55 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 120 mm OD and 29 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7311B support?",
        "a": "One 7311B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7311B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,500 r/min and the oil rating 7,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7311B?",
        "a": "The 55/120/29 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 87 kN / C0 56.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7311B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=129",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7311b",
      "7311B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ311",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ311",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 55,
    "D_mm": 120,
    "B_mm": 29,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 118,
    "static_load_kN": 170,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 7.3,
    "limiting_speed_rpm": 4600,
    "max_rpm": 4600,
    "speed_oil_rpm": 6100,
    "weight_g": 1760,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN QJ311 belongs to the heavy-duty QJ300 four-point family: the catalogue boundary dimensions read 55 / 120 / 29 mm (bore / OD / width). Decoding QJ311: QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family), with the last two digits 11 give the bore by the standard code table (55 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. Catalogue dynamic rating C is 118 kN against C0 170 kN — a C0/C ratio of 1.44 that is typical of an angular-contact contact ellipse. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Heat-mounting to 80-90 deg C is the clean route onto a 55 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "conveyor drive and tension-drum shafts",
      "agricultural gearbox and PTO shaft supports",
      "printing-press cylinder and folder shafts",
      "machine-tool spindle cartridges and driven tooling"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "In this size class the common miss is lubrication interval, not fit — a 55 mm spindle at the catalogue speeds needs a calculated relubrication plan, not a calendar one.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "The C0 of 170 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single QJ311 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 118/170 kN ratings and 7.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ311; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ311?",
        "a": "QJ311 is a four-point contact ball bearing to ISO 15: 55 mm bore, 120 mm outside diameter, 29 mm width (2.165 x 4.724 x 1.142 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 118 kN, C0 170 kN and a 7.3 kN fatigue load limit Pu; the grease limiting speed is 4,600 r/min and the oil rating 6,100 r/min; mass about 1760 g."
      },
      {
        "q": "How is the QJ311 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 11 give the bore by the standard code table (55 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 120 mm OD and 29 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ311 support?",
        "a": "QJ311 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ311?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,600 r/min and the oil rating 6,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ311?",
        "a": "The 55/120/29 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 118 kN / C0 170 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ311",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj311",
      "QJ311"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7912",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7912",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 60,
    "D_mm": 85,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 20,
    "static_load_kN": 17.4,
    "cage_type": "polymer_PA66",
    "fatigue_load_limit_kN": 1.16,
    "limiting_speed_rpm": 7800,
    "max_rpm": 7800,
    "speed_oil_rpm": 10000,
    "weight_g": 230,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 60 x 85 x 13 mm, NTN 7912 sits in the extra-light, high-speed 7900 single-row family of the angular-contact programme. The designation breaks down as 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 12 encodes the 60 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The radial section height here is 12.5 mm, and the catalogue couples that with C 20 kN / C0 17.4 kN. For a 60 mm shaft with combined load, the practical shortlist is this series, its 7000-series standard section, and — where thrust reverses — a back-to-back pair rather than a single row. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 60 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 17.4 kN really covers the worst static case before substituting it for a 7000.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7912 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 20/17.4 kN ratings and 1.16 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7912; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7912?",
        "a": "7912 is a single-row angular contact ball bearing to ISO 15: 60 mm bore, 85 mm outside diameter, 13 mm width (2.362 x 3.346 x 0.512 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 20 kN, C0 17.4 kN and a 1.16 kN fatigue load limit Pu; the grease limiting speed is 7,800 r/min and the oil rating 10,000 r/min; mass about 230 g."
      },
      {
        "q": "How is the 7912 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 12 encodes the 60 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 85 mm OD and 13 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7912 support?",
        "a": "One 7912 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7912?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,800 r/min and the oil rating 10,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7912?",
        "a": "The 60/85/13 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 20 kN / C0 17.4 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7912",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7912"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7012-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7012",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 60,
    "D_mm": 95,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 35.5,
    "static_load_kN": 28.1,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 1.99,
    "limiting_speed_rpm": 7200,
    "max_rpm": 7200,
    "speed_oil_rpm": 9600,
    "weight_g": 478,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The standard-section 7000 single-row family entry 7012 carries a 60 mm bore in a 95 mm outside diameter, 18 mm wide envelope. Reading the code: 70 is the single-row dimension series (standard-section 7000 single-row family), 12 encodes the 60 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Size selection is usually finished by checking that the C0 of 28.1 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 60 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 7,200 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 7,200 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 35.5/28.1 kN ratings and 1.99 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7012; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7012?",
        "a": "7012 is a single-row angular contact ball bearing to ISO 15: 60 mm bore, 95 mm outside diameter, 18 mm width (2.362 x 3.74 x 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 35.5 kN, C0 28.1 kN and a 1.99 kN fatigue load limit Pu; the grease limiting speed is 7,200 r/min and the oil rating 9,600 r/min; mass about 478 g."
      },
      {
        "q": "How is the 7012 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 12 encodes the 60 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 95 mm OD and 18 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7012 support?",
        "a": "One 7012 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7012?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,200 r/min and the oil rating 9,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7012?",
        "a": "The 60/95/18 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 35.5 kN / C0 28.1 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7012",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7012",
      "7012-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5212S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5212S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 36.5,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 69,
    "static_load_kN": 62,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 3.8,
    "limiting_speed_rpm": 3800,
    "max_rpm": 3800,
    "speed_oil_rpm": 5000,
    "weight_g": 1330,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "5212S is an NTN double-row angular contact ball bearing: medium-duty 5200S double-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 60 x 110 x 36.5 mm. Two fields make up the code — 52 is the double-row dimension series (medium-duty 5200S double-row family) and 12 encodes the 60 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. Catalogue mass is about 1330 g, which at this 25.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 60 mm bore give the working limits. ",
    "applications": [
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 60 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5212S without re-checking axial float, heat and housing width — the kinematics differ.",
      "Do not pair two random 5212S bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 69/62 kN ratings and 3.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5212S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5212S?",
        "a": "5212S is a double-row angular contact ball bearing to ISO 15: 60 mm bore, 110 mm outside diameter, 36.5 mm width (2.362 x 4.331 x 1.437 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 69 kN, C0 62 kN and a 3.8 kN fatigue load limit Pu; the grease limiting speed is 3,800 r/min and the oil rating 5,000 r/min; mass about 1330 g."
      },
      {
        "q": "How is the 5212S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 12 encodes the 60 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 110 mm OD and 36.5 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5212S support?",
        "a": "5212S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5212S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,800 r/min and the oil rating 5,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5212S?",
        "a": "The 60/110/36.5 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 69 kN / C0 62 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5212S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5212s",
      "5212S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7212-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7212",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 68.5,
    "static_load_kN": 49,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 3.85,
    "limiting_speed_rpm": 6600,
    "max_rpm": 6600,
    "speed_oil_rpm": 8800,
    "weight_g": 765,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7212 is the 60 mm bore member of NTN's medium-duty 7200 single-row family, with a 110 mm outside diameter and 22 mm section width. NTN builds the number from 72 is the single-row dimension series (medium-duty 7200 single-row family), then 12 encodes the 60 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Against a deep-groove bearing of the same 60 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Grease quantity matters as much as grade at 6,600 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 60 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7212 without re-checking axial float, heat and housing width — the kinematics differ.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 6,600 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 68.5/49 kN ratings and 3.85 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7212; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7212?",
        "a": "7212 is a single-row angular contact ball bearing to ISO 15: 60 mm bore, 110 mm outside diameter, 22 mm width (2.362 x 4.331 x 0.866 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 68.5 kN, C0 49 kN and a 3.85 kN fatigue load limit Pu; the grease limiting speed is 6,600 r/min and the oil rating 8,800 r/min; mass about 765 g."
      },
      {
        "q": "How is the 7212 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 12 encodes the 60 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 110 mm OD and 22 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7212 support?",
        "a": "One 7212 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7212?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,600 r/min and the oil rating 8,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7212?",
        "a": "The 60/110/22 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 68.5 kN / C0 49 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7212",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7212-ACCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7212-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7212-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7212-BECBPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7212-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7212-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7212",
      "7212-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7212B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7212B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 62,
    "static_load_kN": 44.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 3.4,
    "limiting_speed_rpm": 5700,
    "max_rpm": 5700,
    "speed_oil_rpm": 7600,
    "weight_g": 780,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 60 x 110 x 22 mm, NTN 7212B sits in the medium-duty 7200 single-row family of the angular-contact programme. NTN builds the number from 72 is the single-row dimension series (medium-duty 7200 single-row family), then 12 encodes the 60 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). At roughly 25.0 mm of radial section, the catalogue still quotes 62 kN dynamic capacity for the 60 mm bore. Choose the medium-duty 7200 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 60 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "On a 60 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 62/44.5 kN ratings and 3.4 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7212B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7212B?",
        "a": "7212B is a single-row angular contact ball bearing to ISO 15: 60 mm bore, 110 mm outside diameter, 22 mm width (2.362 x 4.331 x 0.866 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 62 kN, C0 44.5 kN and a 3.4 kN fatigue load limit Pu; the grease limiting speed is 5,700 r/min and the oil rating 7,600 r/min; mass about 780 g."
      },
      {
        "q": "How is the 7212B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 12 encodes the 60 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 110 mm OD and 22 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7212B support?",
        "a": "One 7212B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7212B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,700 r/min and the oil rating 7,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7212B?",
        "a": "The 60/110/22 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 62 kN / C0 44.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7212B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7212b",
      "7212B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ212",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ212",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 86,
    "static_load_kN": 138,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 5.9,
    "limiting_speed_rpm": 4700,
    "max_rpm": 4700,
    "speed_oil_rpm": 6300,
    "weight_g": 980,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, QJ212 appears as a medium-duty QJ200 four-point family bearing of 60 mm bore, 110 mm outside diameter and 22 mm width. The designation breaks down as QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 12 give the bore by the standard code table (60 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The static margin, C0 138 kN versus C 86 kN, is what supports slow oscillating duty and shock without immediate brinelling. Size selection is usually finished by checking that the C0 of 138 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 60 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Do not pair two random QJ212 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single QJ212 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Do not pair two random QJ212 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 86/138 kN ratings and 5.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ212; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ212?",
        "a": "QJ212 is a four-point contact ball bearing to ISO 15: 60 mm bore, 110 mm outside diameter, 22 mm width (2.362 x 4.331 x 0.866 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 86 kN, C0 138 kN and a 5.9 kN fatigue load limit Pu; the grease limiting speed is 4,700 r/min and the oil rating 6,300 r/min; mass about 980 g."
      },
      {
        "q": "How is the QJ212 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 12 give the bore by the standard code table (60 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 110 mm OD and 22 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ212 support?",
        "a": "QJ212 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ212?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,700 r/min and the oil rating 6,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ212?",
        "a": "The 60/110/22 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 86 kN / C0 138 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ212",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj212",
      "QJ212"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5312S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5312S",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 60,
    "D_mm": 130,
    "B_mm": 54,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 125,
    "static_load_kN": 98.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 6,
    "limiting_speed_rpm": 3400,
    "max_rpm": 3400,
    "speed_oil_rpm": 4500,
    "weight_g": 2920,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "5312S is the 60 mm bore member of NTN's heavy-duty 5300S double-row family, with a 130 mm outside diameter and 54 mm section width. The designation breaks down as 53 is the double-row dimension series (heavy-duty 5300S double-row family); 12 encodes the 60 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The built-in back-to-back contact lines give the double-row bearing its two-direction thrust and moment capacity from one ring set. The 60/130/54 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 60 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "Grease rated for deep-groove motor duty is not automatically right at 3,400 r/min with preload; check the grease speed factor against the catalogue figure.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "A 5312S mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 125/98.5 kN ratings and 6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5312S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5312S?",
        "a": "5312S is a double-row angular contact ball bearing to ISO 15: 60 mm bore, 130 mm outside diameter, 54 mm width (2.362 x 5.118 x 2.126 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 125 kN, C0 98.5 kN and a 6 kN fatigue load limit Pu; the grease limiting speed is 3,400 r/min and the oil rating 4,500 r/min; mass about 2920 g."
      },
      {
        "q": "How is the 5312S designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 12 encodes the 60 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 130 mm OD and 54 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5312S support?",
        "a": "5312S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5312S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,400 r/min and the oil rating 4,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5312S?",
        "a": "The 60/130/54 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 125 kN / C0 98.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5312S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5312s",
      "5312S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7312-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7312",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 60,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 109,
    "static_load_kN": 71.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 5.6,
    "limiting_speed_rpm": 5900,
    "max_rpm": 5900,
    "speed_oil_rpm": 7900,
    "weight_g": 1740,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 60 x 130 x 31 mm, NTN 7312 sits in the heavy-duty 7300 single-row family of the angular-contact programme. Decoding 7312: 73 is the single-row dimension series (heavy-duty 7300 single-row family), with 12 encodes the 60 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. NTN prints 109 kN dynamic and 71.5 kN static for this size and a 5.6 kN fatigue load limit Pu. For a 60 mm shaft with combined load, the practical shortlist is this series, its 7200-series lighter section, and — where thrust reverses — a back-to-back pair rather than a single row. A 60 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "Bearings of 60 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A 7312 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7312 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7312 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 109/71.5 kN ratings and 5.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7312; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7312?",
        "a": "7312 is a single-row angular contact ball bearing to ISO 15: 60 mm bore, 130 mm outside diameter, 31 mm width (2.362 x 5.118 x 1.22 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 109 kN, C0 71.5 kN and a 5.6 kN fatigue load limit Pu; the grease limiting speed is 5,900 r/min and the oil rating 7,900 r/min; mass about 1740 g."
      },
      {
        "q": "How is the 7312 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 12 encodes the 60 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 130 mm OD and 31 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7312 support?",
        "a": "One 7312 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7312?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,900 r/min and the oil rating 7,900 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7312?",
        "a": "The 60/130/31 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 109 kN / C0 71.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7312",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7312-ACCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7312-BECBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7312-BECBP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7312-BECBPH",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7312-BECBY",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7312-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7312",
      "7312-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7312B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7312B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 60,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 99.5,
    "static_load_kN": 66,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 5.15,
    "limiting_speed_rpm": 5100,
    "max_rpm": 5100,
    "speed_oil_rpm": 6800,
    "weight_g": 1770,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7312B belongs to the heavy-duty 7300 single-row family: the catalogue boundary dimensions read 60 / 130 / 31 mm (bore / OD / width). Two fields make up the code — 73 is the single-row dimension series (heavy-duty 7300 single-row family) and 12 encodes the 60 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Grease quantity matters as much as grade at 5,100 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 60 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The C0 of 66 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 5,100 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 99.5/66 kN ratings and 5.15 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7312B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7312B?",
        "a": "7312B is a single-row angular contact ball bearing to ISO 15: 60 mm bore, 130 mm outside diameter, 31 mm width (2.362 x 5.118 x 1.22 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 99.5 kN, C0 66 kN and a 5.15 kN fatigue load limit Pu; the grease limiting speed is 5,100 r/min and the oil rating 6,800 r/min; mass about 1770 g."
      },
      {
        "q": "How is the 7312B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 12 encodes the 60 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 130 mm OD and 31 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7312B support?",
        "a": "One 7312B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7312B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,100 r/min and the oil rating 6,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7312B?",
        "a": "The 60/130/31 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 99.5 kN / C0 66 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7312B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7312b",
      "7312B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ312",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ312",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 60,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 135,
    "static_load_kN": 198,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 8.5,
    "limiting_speed_rpm": 4200,
    "max_rpm": 4200,
    "speed_oil_rpm": 5700,
    "weight_g": 2180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The heavy-duty QJ300 four-point family entry QJ312 carries a 60 mm bore in a 130 mm outside diameter, 31 mm wide envelope. NTN builds the number from QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family), then the last two digits 12 give the bore by the standard code table (60 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. At roughly 35.0 mm of radial section, the catalogue still quotes 135 kN dynamic capacity for the 60 mm bore. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 60 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Grease rated for deep-groove motor duty is not automatically right at 4,200 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 135/198 kN ratings and 8.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ312; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ312?",
        "a": "QJ312 is a four-point contact ball bearing to ISO 15: 60 mm bore, 130 mm outside diameter, 31 mm width (2.362 x 5.118 x 1.22 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 135 kN, C0 198 kN and a 8.5 kN fatigue load limit Pu; the grease limiting speed is 4,200 r/min and the oil rating 5,700 r/min; mass about 2180 g."
      },
      {
        "q": "How is the QJ312 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 12 give the bore by the standard code table (60 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 130 mm OD and 31 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ312 support?",
        "a": "QJ312 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ312?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,200 r/min and the oil rating 5,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ312?",
        "a": "The 60/130/31 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 135 kN / C0 198 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ312",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj312",
      "QJ312"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7913",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7913",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 65,
    "D_mm": 90,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 20.2,
    "static_load_kN": 18,
    "cage_type": "polymer_PA66",
    "fatigue_load_limit_kN": 1.2,
    "limiting_speed_rpm": 7200,
    "max_rpm": 7200,
    "speed_oil_rpm": 9600,
    "weight_g": 245,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7913 is the 65 mm bore member of NTN's extra-light, high-speed 7900 single-row family, with a 90 mm outside diameter and 13 mm section width. Reading the code: 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), 13 encodes the 65 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 30 deg contact angle is the lever that turns the 18 kN static rating into useful one-direction thrust capacity. Against a deep-groove bearing of the same 65 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 65 mm bore give the working limits. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 65 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 18 kN really covers the worst static case before substituting it for a 7000.",
      "The C0 of 18 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Do not pair two random 7913 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "A 7913 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 20.2/18 kN ratings and 1.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7913; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7913?",
        "a": "7913 is a single-row angular contact ball bearing to ISO 15: 65 mm bore, 90 mm outside diameter, 13 mm width (2.559 x 3.543 x 0.512 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 20.2 kN, C0 18 kN and a 1.2 kN fatigue load limit Pu; the grease limiting speed is 7,200 r/min and the oil rating 9,600 r/min; mass about 245 g."
      },
      {
        "q": "How is the 7913 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 13 encodes the 65 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 90 mm OD and 13 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7913 support?",
        "a": "One 7913 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7913?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 7,200 r/min and the oil rating 9,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7913?",
        "a": "The 65/90/13 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 20.2 kN / C0 18 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7913",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7913"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7013-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7013",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 65,
    "D_mm": 100,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 37.5,
    "static_load_kN": 31.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.18,
    "limiting_speed_rpm": 6700,
    "max_rpm": 6700,
    "speed_oil_rpm": 9000,
    "weight_g": 509,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 65 x 100 x 18 mm, NTN 7013 sits in the standard-section 7000 single-row family of the angular-contact programme. Decoding 7013: 70 is the single-row dimension series (standard-section 7000 single-row family), with 13 encodes the 65 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue mass is about 509 g, which at this 17.5 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. The 65/100/18 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "Bearings of 65 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 37.5/31.5 kN ratings and 2.18 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7013; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7013?",
        "a": "7013 is a single-row angular contact ball bearing to ISO 15: 65 mm bore, 100 mm outside diameter, 18 mm width (2.559 x 3.937 x 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 37.5 kN, C0 31.5 kN and a 2.18 kN fatigue load limit Pu; the grease limiting speed is 6,700 r/min and the oil rating 9,000 r/min; mass about 509 g."
      },
      {
        "q": "How is the 7013 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 13 encodes the 65 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 100 mm OD and 18 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7013 support?",
        "a": "One 7013 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7013?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,700 r/min and the oil rating 9,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7013?",
        "a": "The 65/100/18 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 37.5 kN / C0 31.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7013",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7013",
      "7013-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5213S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5213S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 38.1,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 76.5,
    "static_load_kN": 69,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 4.2,
    "limiting_speed_rpm": 3600,
    "max_rpm": 3600,
    "speed_oil_rpm": 4500,
    "weight_g": 1710,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 5200S double-row family entry 5213S carries a 65 mm bore in a 120 mm outside diameter, 38.1 mm wide envelope. NTN builds the number from 52 is the double-row dimension series (medium-duty 5200S double-row family), then 13 encodes the 65 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The built-in back-to-back contact lines give the double-row bearing its two-direction thrust and moment capacity from one ring set. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 65 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "A 5213S mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 76.5/69 kN ratings and 4.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5213S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5213S?",
        "a": "5213S is a double-row angular contact ball bearing to ISO 15: 65 mm bore, 120 mm outside diameter, 38.1 mm width (2.559 x 4.724 x 1.5 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 76.5 kN, C0 69 kN and a 4.2 kN fatigue load limit Pu; the grease limiting speed is 3,600 r/min and the oil rating 4,500 r/min; mass about 1710 g."
      },
      {
        "q": "How is the 5213S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 13 encodes the 65 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 120 mm OD and 38.1 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5213S support?",
        "a": "5213S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5213S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,600 r/min and the oil rating 4,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5213S?",
        "a": "The 65/120/38.1 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 76.5 kN / C0 69 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5213S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5213s",
      "5213S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7213-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7213",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 78,
    "static_load_kN": 58,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 4.55,
    "limiting_speed_rpm": 6100,
    "max_rpm": 6100,
    "speed_oil_rpm": 8100,
    "weight_g": 962,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 65 x 120 x 23 mm, NTN 7213 sits in the medium-duty 7200 single-row family of the angular-contact programme. Reading the code: 72 is the single-row dimension series (medium-duty 7200 single-row family), 13 encodes the 65 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The radial section height here is 27.5 mm, and the catalogue couples that with C 78 kN / C0 58 kN. Choose the medium-duty 7200 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. A 65 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 65 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Do not pair two random 7213 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 6,100 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 78/58 kN ratings and 4.55 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7213; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7213?",
        "a": "7213 is a single-row angular contact ball bearing to ISO 15: 65 mm bore, 120 mm outside diameter, 23 mm width (2.559 x 4.724 x 0.906 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 78 kN, C0 58 kN and a 4.55 kN fatigue load limit Pu; the grease limiting speed is 6,100 r/min and the oil rating 8,100 r/min; mass about 962 g."
      },
      {
        "q": "How is the 7213 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 13 encodes the 65 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 120 mm OD and 23 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7213 support?",
        "a": "One 7213 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7213?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,100 r/min and the oil rating 8,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7213?",
        "a": "The 65/120/23 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 78 kN / C0 58 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7213",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7213-ACCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7213-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7213-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7213-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7213-BEGAPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7213-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7213",
      "7213-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7213B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7213B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 70.5,
    "static_load_kN": 52.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 3.95,
    "limiting_speed_rpm": 5200,
    "max_rpm": 5200,
    "speed_oil_rpm": 7000,
    "weight_g": 981,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7213B is an NTN single-row angular contact ball bearing: medium-duty 7200 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 65 x 120 x 23 mm. Reading the code: 72 is the single-row dimension series (medium-duty 7200 single-row family), 13 encodes the 65 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Against a deep-groove bearing of the same 65 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. A 65 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 65 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "A 7213B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 5,200 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 70.5/52.5 kN ratings and 3.95 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7213B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7213B?",
        "a": "7213B is a single-row angular contact ball bearing to ISO 15: 65 mm bore, 120 mm outside diameter, 23 mm width (2.559 x 4.724 x 0.906 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 70.5 kN, C0 52.5 kN and a 3.95 kN fatigue load limit Pu; the grease limiting speed is 5,200 r/min and the oil rating 7,000 r/min; mass about 981 g."
      },
      {
        "q": "How is the 7213B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 13 encodes the 65 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 120 mm OD and 23 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7213B support?",
        "a": "One 7213B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7213B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,200 r/min and the oil rating 7,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7213B?",
        "a": "The 65/120/23 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 70.5 kN / C0 52.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7213B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7213b",
      "7213B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ213",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ213",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 93.5,
    "static_load_kN": 153,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 6.55,
    "limiting_speed_rpm": 4400,
    "max_rpm": 4400,
    "speed_oil_rpm": 5800,
    "weight_g": 1240,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN QJ213 belongs to the medium-duty QJ200 four-point family: the catalogue boundary dimensions read 65 / 120 / 23 mm (bore / OD / width). Reading the code: QJ2 is the four-point dimension series (medium-duty QJ200 four-point family), the last two digits 13 give the bore by the standard code table (65 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The oil rating of 5,800 r/min sits 1,400 r/min above the 4,400 r/min grease figure — a 1.32x step that says how much headroom oil cooling buys. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Grease quantity matters as much as grade at 4,400 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 65 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "The 4,400 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Grease rated for deep-groove motor duty is not automatically right at 4,400 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Grease rated for deep-groove motor duty is not automatically right at 4,400 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 93.5/153 kN ratings and 6.55 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ213; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ213?",
        "a": "QJ213 is a four-point contact ball bearing to ISO 15: 65 mm bore, 120 mm outside diameter, 23 mm width (2.559 x 4.724 x 0.906 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 93.5 kN, C0 153 kN and a 6.55 kN fatigue load limit Pu; the grease limiting speed is 4,400 r/min and the oil rating 5,800 r/min; mass about 1240 g."
      },
      {
        "q": "How is the QJ213 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 13 give the bore by the standard code table (65 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 120 mm OD and 23 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ213 support?",
        "a": "QJ213 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ213?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,400 r/min and the oil rating 5,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ213?",
        "a": "The 65/120/23 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 93.5 kN / C0 153 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ213",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj213",
      "QJ213"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5313S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5313S",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 58.7,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 142,
    "static_load_kN": 113,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 7,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "speed_oil_rpm": 4300,
    "weight_g": 3670,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5313S appears as a heavy-duty 5300S double-row family bearing of 65 mm bore, 140 mm outside diameter and 58.7 mm width. Two fields make up the code — 53 is the double-row dimension series (heavy-duty 5300S double-row family) and 13 encodes the 65 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. With C 142 kN and C0 113 kN, each mm of bore carries about 2.18 kN of dynamic rating. Size selection is usually finished by checking that the C0 of 113 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Grease quantity matters as much as grade at 3,200 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 65 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "On a 65 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The C0 of 113 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "On a 65 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 142/113 kN ratings and 7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5313S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5313S?",
        "a": "5313S is a double-row angular contact ball bearing to ISO 15: 65 mm bore, 140 mm outside diameter, 58.7 mm width (2.559 x 5.512 x 2.311 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 142 kN, C0 113 kN and a 7 kN fatigue load limit Pu; the grease limiting speed is 3,200 r/min and the oil rating 4,300 r/min; mass about 3670 g."
      },
      {
        "q": "How is the 5313S designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 13 encodes the 65 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 140 mm OD and 58.7 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5313S support?",
        "a": "5313S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5313S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,200 r/min and the oil rating 4,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5313S?",
        "a": "The 65/140/58.7 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 142 kN / C0 113 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5313S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5313s",
      "5313S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7313-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7313",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 123,
    "static_load_kN": 82,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 6.35,
    "limiting_speed_rpm": 5500,
    "max_rpm": 5500,
    "speed_oil_rpm": 7300,
    "weight_g": 2110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7313 is the 65 mm bore member of NTN's heavy-duty 7300 single-row family, with a 140 mm outside diameter and 33 mm section width. The designation breaks down as 73 is the single-row dimension series (heavy-duty 7300 single-row family); 13 encodes the 65 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. A 65 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 65 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7313 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 5,500 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 123/82 kN ratings and 6.35 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7313; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7313?",
        "a": "7313 is a single-row angular contact ball bearing to ISO 15: 65 mm bore, 140 mm outside diameter, 33 mm width (2.559 x 5.512 x 1.299 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 123 kN, C0 82 kN and a 6.35 kN fatigue load limit Pu; the grease limiting speed is 5,500 r/min and the oil rating 7,300 r/min; mass about 2110 g."
      },
      {
        "q": "How is the 7313 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 13 encodes the 65 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 140 mm OD and 33 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7313 support?",
        "a": "One 7313 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7313?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,500 r/min and the oil rating 7,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7313?",
        "a": "The 65/140/33 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 123 kN / C0 82 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7313",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7313-ACCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7313-BECBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7313-BECBP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7313-BECBPH",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7313-BECBY",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7313-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7313",
      "7313-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7313B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7313B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 113,
    "static_load_kN": 75.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 5.85,
    "limiting_speed_rpm": 4700,
    "max_rpm": 4700,
    "speed_oil_rpm": 6300,
    "weight_g": 2150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7313B is the 65 mm bore member of NTN's heavy-duty 7300 single-row family, with a 140 mm outside diameter and 33 mm section width. NTN builds the number from 73 is the single-row dimension series (heavy-duty 7300 single-row family), then 13 encodes the 65 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The radial section height here is 37.5 mm, and the catalogue couples that with C 113 kN / C0 75.5 kN. For a 65 mm shaft with combined load, the practical shortlist is this series, its 7200-series lighter section, and — where thrust reverses — a back-to-back pair rather than a single row. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 65 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "The 4,700 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Grease rated for deep-groove motor duty is not automatically right at 4,700 r/min with preload; check the grease speed factor against the catalogue figure.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 113/75.5 kN ratings and 5.85 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7313B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7313B?",
        "a": "7313B is a single-row angular contact ball bearing to ISO 15: 65 mm bore, 140 mm outside diameter, 33 mm width (2.559 x 5.512 x 1.299 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 113 kN, C0 75.5 kN and a 5.85 kN fatigue load limit Pu; the grease limiting speed is 4,700 r/min and the oil rating 6,300 r/min; mass about 2150 g."
      },
      {
        "q": "How is the 7313B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 13 encodes the 65 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 140 mm OD and 33 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7313B support?",
        "a": "One 7313B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7313B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,700 r/min and the oil rating 6,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7313B?",
        "a": "The 65/140/33 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 113 kN / C0 75.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7313B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7313b",
      "7313B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ313",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ313",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 153,
    "static_load_kN": 228,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 9.7,
    "limiting_speed_rpm": 3900,
    "max_rpm": 3900,
    "speed_oil_rpm": 5200,
    "weight_g": 2700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 65 x 140 x 33 mm, NTN QJ313 sits in the heavy-duty QJ300 four-point family of the angular-contact programme. The designation breaks down as QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 13 give the bore by the standard code table (65 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. NTN prints 153 kN dynamic and 228 kN static for this size and a 9.7 kN fatigue load limit Pu. Choose the heavy-duty QJ300 four-point family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Grease quantity matters as much as grade at 3,900 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 65 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "A QJ313 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The C0 of 228 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single QJ313 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 153/228 kN ratings and 9.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ313; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ313?",
        "a": "QJ313 is a four-point contact ball bearing to ISO 15: 65 mm bore, 140 mm outside diameter, 33 mm width (2.559 x 5.512 x 1.299 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 153 kN, C0 228 kN and a 9.7 kN fatigue load limit Pu; the grease limiting speed is 3,900 r/min and the oil rating 5,200 r/min; mass about 2700 g."
      },
      {
        "q": "How is the QJ313 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 13 give the bore by the standard code table (65 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 140 mm OD and 33 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ313 support?",
        "a": "QJ313 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ313?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,900 r/min and the oil rating 5,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ313?",
        "a": "The 65/140/33 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 153 kN / C0 228 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ313",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj313",
      "QJ313"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7914",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7914",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 70,
    "D_mm": 100,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 29,
    "static_load_kN": 26.2,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 1.74,
    "limiting_speed_rpm": 6700,
    "max_rpm": 6700,
    "speed_oil_rpm": 9000,
    "weight_g": 397,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the extra-light, high-speed 7900 single-row family, 7914 measures 70 mm across the bore, 100 mm over the outer ring and 16 mm across the faces. Two fields make up the code — 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family) and 14 encodes the 70 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. On speed, the grease limiting speed is 6,700 r/min and the oil rating 9,000 r/min. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Heat-mounting to 80-90 deg C is the clean route onto a 70 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 70 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 26.2 kN really covers the worst static case before substituting it for a 7000.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "A 7914 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The C0 of 26.2 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 29/26.2 kN ratings and 1.74 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7914; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7914?",
        "a": "7914 is a single-row angular contact ball bearing to ISO 15: 70 mm bore, 100 mm outside diameter, 16 mm width (2.756 x 3.937 x 0.63 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 29 kN, C0 26.2 kN and a 1.74 kN fatigue load limit Pu; the grease limiting speed is 6,700 r/min and the oil rating 9,000 r/min; mass about 397 g."
      },
      {
        "q": "How is the 7914 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 14 encodes the 70 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 100 mm OD and 16 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7914 support?",
        "a": "One 7914 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7914?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,700 r/min and the oil rating 9,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7914?",
        "a": "The 70/100/16 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 29 kN / C0 26.2 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7914",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7914"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7014-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7014",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 70,
    "D_mm": 110,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 47.5,
    "static_load_kN": 39.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.78,
    "limiting_speed_rpm": 6200,
    "max_rpm": 6200,
    "speed_oil_rpm": 8300,
    "weight_g": 705,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7014 is the 70 mm bore member of NTN's standard-section 7000 single-row family, with a 110 mm outside diameter and 20 mm section width. The designation breaks down as 70 is the single-row dimension series (standard-section 7000 single-row family); 14 encodes the 70 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The radial section height here is 20.0 mm, and the catalogue couples that with C 47.5 kN / C0 39.5 kN. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 70 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "On a 70 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Grease rated for deep-groove motor duty is not automatically right at 6,200 r/min with preload; check the grease speed factor against the catalogue figure.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 47.5/39.5 kN ratings and 2.78 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7014; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7014?",
        "a": "7014 is a single-row angular contact ball bearing to ISO 15: 70 mm bore, 110 mm outside diameter, 20 mm width (2.756 x 4.331 x 0.787 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 47.5 kN, C0 39.5 kN and a 2.78 kN fatigue load limit Pu; the grease limiting speed is 6,200 r/min and the oil rating 8,300 r/min; mass about 705 g."
      },
      {
        "q": "How is the 7014 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 14 encodes the 70 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 110 mm OD and 20 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7014 support?",
        "a": "One 7014 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7014?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,200 r/min and the oil rating 8,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7014?",
        "a": "The 70/110/20 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 47.5 kN / C0 39.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7014",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7014",
      "7014-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5214S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5214S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 70,
    "D_mm": 125,
    "B_mm": 39.7,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 94,
    "static_load_kN": 82,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 5,
    "limiting_speed_rpm": 3400,
    "max_rpm": 3400,
    "speed_oil_rpm": 4500,
    "weight_g": 1750,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 5200S double-row family, 5214S measures 70 mm across the bore, 125 mm over the outer ring and 39.7 mm across the faces. Reading the code: 52 is the double-row dimension series (medium-duty 5200S double-row family), 14 encodes the 70 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. With C 94 kN and C0 82 kN, each mm of bore carries about 1.34 kN of dynamic rating. The 70/125/39.7 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. A 70 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 70 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "Do not pair two random 5214S bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "On a 70 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 94/82 kN ratings and 5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5214S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5214S?",
        "a": "5214S is a double-row angular contact ball bearing to ISO 15: 70 mm bore, 125 mm outside diameter, 39.7 mm width (2.756 x 4.921 x 1.563 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 94 kN, C0 82 kN and a 5 kN fatigue load limit Pu; the grease limiting speed is 3,400 r/min and the oil rating 4,500 r/min; mass about 1750 g."
      },
      {
        "q": "How is the 5214S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 14 encodes the 70 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 125 mm OD and 39.7 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5214S support?",
        "a": "5214S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5214S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,400 r/min and the oil rating 4,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5214S?",
        "a": "The 70/125/39.7 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 94 kN / C0 82 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5214S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5214s",
      "5214S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7214-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7214",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 70,
    "D_mm": 125,
    "B_mm": 24,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 84.5,
    "static_load_kN": 63.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 5,
    "limiting_speed_rpm": 5700,
    "max_rpm": 5700,
    "speed_oil_rpm": 7600,
    "weight_g": 1090,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7214 is the 70 mm bore member of NTN's medium-duty 7200 single-row family, with a 125 mm outside diameter and 24 mm section width. Decoding 7214: 72 is the single-row dimension series (medium-duty 7200 single-row family), with 14 encodes the 70 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 30 deg contact angle is the lever that turns the 63.5 kN static rating into useful one-direction thrust capacity. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. A 70 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "Bearings of 70 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "A 7214 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 84.5/63.5 kN ratings and 5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7214; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7214?",
        "a": "7214 is a single-row angular contact ball bearing to ISO 15: 70 mm bore, 125 mm outside diameter, 24 mm width (2.756 x 4.921 x 0.945 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 84.5 kN, C0 63.5 kN and a 5 kN fatigue load limit Pu; the grease limiting speed is 5,700 r/min and the oil rating 7,600 r/min; mass about 1090 g."
      },
      {
        "q": "How is the 7214 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 14 encodes the 70 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 125 mm OD and 24 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7214 support?",
        "a": "One 7214 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7214?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,700 r/min and the oil rating 7,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7214?",
        "a": "The 70/125/24 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 84.5 kN / C0 63.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7214",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×125×24 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7214-ACCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7214-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×125×24 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7214-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×125×24 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7214-BECBPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×125×24 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7214-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×125×24 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7214-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×125×24 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7214",
      "7214-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7214B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7214B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 70,
    "D_mm": 125,
    "B_mm": 24,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 76.5,
    "static_load_kN": 58,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 4.35,
    "limiting_speed_rpm": 4900,
    "max_rpm": 4900,
    "speed_oil_rpm": 6500,
    "weight_g": 1110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 7200 single-row family entry 7214B carries a 70 mm bore in a 125 mm outside diameter, 24 mm wide envelope. Decoding 7214B: 72 is the single-row dimension series (medium-duty 7200 single-row family), with 14 encodes the 70 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The radial section height here is 27.5 mm, and the catalogue couples that with C 76.5 kN / C0 58 kN. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "Bearings of 70 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The C0 of 58 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 76.5/58 kN ratings and 4.35 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7214B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7214B?",
        "a": "7214B is a single-row angular contact ball bearing to ISO 15: 70 mm bore, 125 mm outside diameter, 24 mm width (2.756 x 4.921 x 0.945 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 76.5 kN, C0 58 kN and a 4.35 kN fatigue load limit Pu; the grease limiting speed is 4,900 r/min and the oil rating 6,500 r/min; mass about 1110 g."
      },
      {
        "q": "How is the 7214B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 14 encodes the 70 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 125 mm OD and 24 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7214B support?",
        "a": "One 7214B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7214B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,900 r/min and the oil rating 6,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7214B?",
        "a": "The 70/125/24 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 76.5 kN / C0 58 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7214B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7214b",
      "7214B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ214",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ214",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 70,
    "D_mm": 125,
    "B_mm": 24,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 102,
    "static_load_kN": 168,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 7.15,
    "limiting_speed_rpm": 4000,
    "max_rpm": 4000,
    "speed_oil_rpm": 5400,
    "weight_g": 1360,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty QJ200 four-point family entry QJ214 carries a 70 mm bore in a 125 mm outside diameter, 24 mm wide envelope. Two fields make up the code — QJ2 is the four-point dimension series (medium-duty QJ200 four-point family) and the last two digits 14 give the bore by the standard code table (70 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. Catalogue dynamic rating C is 102 kN against C0 168 kN — a C0/C ratio of 1.65 that is typical of an angular-contact contact ellipse. For a 70 mm shaft with combined load, the practical shortlist is this series, its neighbouring dimension series, and — where thrust reverses — a back-to-back pair rather than a single row. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 70 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "On a 70 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The C0 of 168 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 102/168 kN ratings and 7.15 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ214; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ214?",
        "a": "QJ214 is a four-point contact ball bearing to ISO 15: 70 mm bore, 125 mm outside diameter, 24 mm width (2.756 x 4.921 x 0.945 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 102 kN, C0 168 kN and a 7.15 kN fatigue load limit Pu; the grease limiting speed is 4,000 r/min and the oil rating 5,400 r/min; mass about 1360 g."
      },
      {
        "q": "How is the QJ214 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 14 give the bore by the standard code table (70 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 125 mm OD and 24 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ214 support?",
        "a": "QJ214 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ214?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,000 r/min and the oil rating 5,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ214?",
        "a": "The 70/125/24 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 102 kN / C0 168 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ214",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj214",
      "QJ214"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5314S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5314S",
    "series": "5300S-series",
    "type": "angular_contact",
    "d_mm": 70,
    "D_mm": 150,
    "B_mm": 63.5,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 159,
    "static_load_kN": 128,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 7.9,
    "limiting_speed_rpm": 3000,
    "max_rpm": 3000,
    "speed_oil_rpm": 3800,
    "weight_g": 4550,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 70 x 150 x 63.5 mm, NTN 5314S sits in the heavy-duty 5300S double-row family of the angular-contact programme. NTN builds the number from 53 is the double-row dimension series (heavy-duty 5300S double-row family), then 14 encodes the 70 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The oil rating of 3,800 r/min sits 800 r/min above the 3,000 r/min grease figure — a 1.27x step that says how much headroom oil cooling buys. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 70 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "A 5314S mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Grease rated for deep-groove motor duty is not automatically right at 3,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Grease rated for deep-groove motor duty is not automatically right at 3,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 159/128 kN ratings and 7.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5314S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5314S?",
        "a": "5314S is a double-row angular contact ball bearing to ISO 15: 70 mm bore, 150 mm outside diameter, 63.5 mm width (2.756 x 5.906 x 2.5 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 159 kN, C0 128 kN and a 7.9 kN fatigue load limit Pu; the grease limiting speed is 3,000 r/min and the oil rating 3,800 r/min; mass about 4550 g."
      },
      {
        "q": "How is the 5314S designation structured?",
        "a": "53 is the double-row dimension series (heavy-duty 5300S double-row family); 14 encodes the 70 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 150 mm OD and 63.5 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5314S support?",
        "a": "5314S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5314S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,000 r/min and the oil rating 3,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5314S?",
        "a": "The 70/150/63.5 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 159 kN / C0 128 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5314S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5314s",
      "5314S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7314-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7314",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 70,
    "D_mm": 150,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 138,
    "static_load_kN": 93.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 6.95,
    "limiting_speed_rpm": 5100,
    "max_rpm": 5100,
    "speed_oil_rpm": 6800,
    "weight_g": 2560,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 70 x 150 x 35 mm, NTN 7314 sits in the heavy-duty 7300 single-row family of the angular-contact programme. Two fields make up the code — 73 is the single-row dimension series (heavy-duty 7300 single-row family) and 14 encodes the 70 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The radial section height here is 40.0 mm, and the catalogue couples that with C 138 kN / C0 93.5 kN. Against a deep-groove bearing of the same 70 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 70 mm bore give the working limits. ",
    "applications": [
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 70 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Do not pair two random 7314 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Do not pair two random 7314 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 138/93.5 kN ratings and 6.95 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7314; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7314?",
        "a": "7314 is a single-row angular contact ball bearing to ISO 15: 70 mm bore, 150 mm outside diameter, 35 mm width (2.756 x 5.906 x 1.378 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 138 kN, C0 93.5 kN and a 6.95 kN fatigue load limit Pu; the grease limiting speed is 5,100 r/min and the oil rating 6,800 r/min; mass about 2560 g."
      },
      {
        "q": "How is the 7314 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 14 encodes the 70 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 150 mm OD and 35 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7314 support?",
        "a": "One 7314 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7314?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,100 r/min and the oil rating 6,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7314?",
        "a": "The 70/150/35 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 138 kN / C0 93.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7314",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×150×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7314-ACCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×150×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7314-BECBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7314-BECBP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7314-BECBPH",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7314-BECBY",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7314-BEGAPH",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7314-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×150×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7314",
      "7314-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7314B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7314B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 70,
    "D_mm": 150,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 127,
    "static_load_kN": 86,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 6.4,
    "limiting_speed_rpm": 4400,
    "max_rpm": 4400,
    "speed_oil_rpm": 5800,
    "weight_g": 2610,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7314B appears as a heavy-duty 7300 single-row family bearing of 70 mm bore, 150 mm outside diameter and 35 mm width. Reading the code: 73 is the single-row dimension series (heavy-duty 7300 single-row family), 14 encodes the 70 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). On speed, the grease limiting speed is 4,400 r/min and the oil rating 5,800 r/min. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Heat-mounting to 80-90 deg C is the clean route onto a 70 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 70 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7314B without re-checking axial float, heat and housing width — the kinematics differ.",
      "The C0 of 86 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 127/86 kN ratings and 6.4 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7314B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7314B?",
        "a": "7314B is a single-row angular contact ball bearing to ISO 15: 70 mm bore, 150 mm outside diameter, 35 mm width (2.756 x 5.906 x 1.378 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 127 kN, C0 86 kN and a 6.4 kN fatigue load limit Pu; the grease limiting speed is 4,400 r/min and the oil rating 5,800 r/min; mass about 2610 g."
      },
      {
        "q": "How is the 7314B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 14 encodes the 70 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 150 mm OD and 35 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7314B support?",
        "a": "One 7314B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7314B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,400 r/min and the oil rating 5,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7314B?",
        "a": "The 70/150/35 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 127 kN / C0 86 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7314B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7314b",
      "7314B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ314",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ314",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 70,
    "D_mm": 150,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 172,
    "static_load_kN": 260,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 10.7,
    "limiting_speed_rpm": 3600,
    "max_rpm": 3600,
    "speed_oil_rpm": 4800,
    "weight_g": 3270,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "QJ314 is the 70 mm bore member of NTN's heavy-duty QJ300 four-point family, with a 150 mm outside diameter and 35 mm section width. Reading the code: QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family), the last two digits 14 give the bore by the standard code table (70 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Size selection is usually finished by checking that the C0 of 260 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 70 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 3,600 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 172/260 kN ratings and 10.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ314; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ314?",
        "a": "QJ314 is a four-point contact ball bearing to ISO 15: 70 mm bore, 150 mm outside diameter, 35 mm width (2.756 x 5.906 x 1.378 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 172 kN, C0 260 kN and a 10.7 kN fatigue load limit Pu; the grease limiting speed is 3,600 r/min and the oil rating 4,800 r/min; mass about 3270 g."
      },
      {
        "q": "How is the QJ314 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 14 give the bore by the standard code table (70 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 150 mm OD and 35 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ314 support?",
        "a": "QJ314 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ314?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,600 r/min and the oil rating 4,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ314?",
        "a": "The 70/150/35 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 172 kN / C0 260 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ314",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj314",
      "QJ314"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7915",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7915",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 75,
    "D_mm": 105,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 29.4,
    "static_load_kN": 27.1,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 1.8,
    "limiting_speed_rpm": 6300,
    "max_rpm": 6300,
    "speed_oil_rpm": 8400,
    "weight_g": 420,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7915 is an NTN single-row angular contact ball bearing: extra-light, high-speed 7900 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 75 x 105 x 16 mm. Decoding 7915: 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), with 15 encodes the 75 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. With C 29.4 kN and C0 27.1 kN, each mm of bore carries about 0.39 kN of dynamic rating. The 75/105/16 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "Bearings of 75 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 27.1 kN really covers the worst static case before substituting it for a 7000.",
      "A 7915 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 6,300 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "On a 75 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 29.4/27.1 kN ratings and 1.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7915; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7915?",
        "a": "7915 is a single-row angular contact ball bearing to ISO 15: 75 mm bore, 105 mm outside diameter, 16 mm width (2.953 x 4.134 x 0.63 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 29.4 kN, C0 27.1 kN and a 1.8 kN fatigue load limit Pu; the grease limiting speed is 6,300 r/min and the oil rating 8,400 r/min; mass about 420 g."
      },
      {
        "q": "How is the 7915 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 15 encodes the 75 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 105 mm OD and 16 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7915 support?",
        "a": "One 7915 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7915?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 6,300 r/min and the oil rating 8,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7915?",
        "a": "The 75/105/16 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 29.4 kN / C0 27.1 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7915",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7915"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7015-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7015",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 75,
    "D_mm": 115,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 48.5,
    "static_load_kN": 41.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 2.9,
    "limiting_speed_rpm": 5800,
    "max_rpm": 5800,
    "speed_oil_rpm": 7800,
    "weight_g": 745,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 75 x 115 x 20 mm, NTN 7015 sits in the standard-section 7000 single-row family of the angular-contact programme. Two fields make up the code — 70 is the single-row dimension series (standard-section 7000 single-row family) and 15 encodes the 75 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. On speed, the grease limiting speed is 5,800 r/min and the oil rating 7,800 r/min. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Heat-mounting to 80-90 deg C is the clean route onto a 75 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 75 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "On a 75 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The C0 of 41.5 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 48.5/41.5 kN ratings and 2.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7015; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7015?",
        "a": "7015 is a single-row angular contact ball bearing to ISO 15: 75 mm bore, 115 mm outside diameter, 20 mm width (2.953 x 4.528 x 0.787 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 48.5 kN, C0 41.5 kN and a 2.9 kN fatigue load limit Pu; the grease limiting speed is 5,800 r/min and the oil rating 7,800 r/min; mass about 745 g."
      },
      {
        "q": "How is the 7015 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 15 encodes the 75 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 115 mm OD and 20 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7015 support?",
        "a": "One 7015 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7015?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,800 r/min and the oil rating 7,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7015?",
        "a": "The 75/115/20 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 48.5 kN / C0 41.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7015",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7015",
      "7015-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5215S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5215S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 75,
    "D_mm": 130,
    "B_mm": 41.3,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 93.5,
    "static_load_kN": 83,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 5.1,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "speed_oil_rpm": 4300,
    "weight_g": 1880,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 5215S belongs to the medium-duty 5200S double-row family: the catalogue boundary dimensions read 75 / 130 / 41.3 mm (bore / OD / width). Decoding 5215S: 52 is the double-row dimension series (medium-duty 5200S double-row family), with 15 encodes the 75 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The oil rating of 4,300 r/min sits 1,100 r/min above the 3,200 r/min grease figure — a 1.34x step that says how much headroom oil cooling buys. Size selection is usually finished by checking that the C0 of 83 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "Bearings of 75 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "The C0 of 83 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The C0 of 83 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Grease rated for deep-groove motor duty is not automatically right at 3,200 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 93.5/83 kN ratings and 5.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5215S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5215S?",
        "a": "5215S is a double-row angular contact ball bearing to ISO 15: 75 mm bore, 130 mm outside diameter, 41.3 mm width (2.953 x 5.118 x 1.626 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 93.5 kN, C0 83 kN and a 5.1 kN fatigue load limit Pu; the grease limiting speed is 3,200 r/min and the oil rating 4,300 r/min; mass about 1880 g."
      },
      {
        "q": "How is the 5215S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 15 encodes the 75 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 130 mm OD and 41.3 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5215S support?",
        "a": "5215S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5215S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,200 r/min and the oil rating 4,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5215S?",
        "a": "The 75/130/41.3 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 93.5 kN / C0 83 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5215S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5215s",
      "5215S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7215-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7215",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 75,
    "D_mm": 130,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 87.5,
    "static_load_kN": 68.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 5.2,
    "limiting_speed_rpm": 5300,
    "max_rpm": 5300,
    "speed_oil_rpm": 7100,
    "weight_g": 1170,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 75 x 130 x 25 mm, NTN 7215 sits in the medium-duty 7200 single-row family of the angular-contact programme. The designation breaks down as 72 is the single-row dimension series (medium-duty 7200 single-row family); 15 encodes the 75 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. With C 87.5 kN and C0 68.5 kN, each mm of bore carries about 1.17 kN of dynamic rating. Size selection is usually finished by checking that the C0 of 68.5 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 75 mm bore give the working limits. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 75 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Grease rated for deep-groove motor duty is not automatically right at 5,300 r/min with preload; check the grease speed factor against the catalogue figure.",
      "On a 75 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 87.5/68.5 kN ratings and 5.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7215; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7215?",
        "a": "7215 is a single-row angular contact ball bearing to ISO 15: 75 mm bore, 130 mm outside diameter, 25 mm width (2.953 x 5.118 x 0.984 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 87.5 kN, C0 68.5 kN and a 5.2 kN fatigue load limit Pu; the grease limiting speed is 5,300 r/min and the oil rating 7,100 r/min; mass about 1170 g."
      },
      {
        "q": "How is the 7215 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 15 encodes the 75 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 130 mm OD and 25 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7215 support?",
        "a": "One 7215 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7215?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,300 r/min and the oil rating 7,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7215?",
        "a": "The 75/130/25 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 87.5 kN / C0 68.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7215",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7215-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7215-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7215-BECBPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7215-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7215-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×130×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7215",
      "7215-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7215B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7215B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 75,
    "D_mm": 130,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 79,
    "static_load_kN": 62,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 4.5,
    "limiting_speed_rpm": 4500,
    "max_rpm": 4500,
    "speed_oil_rpm": 6000,
    "weight_g": 1190,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 7200 single-row family, 7215B measures 75 mm across the bore, 130 mm over the outer ring and 25 mm across the faces. The designation breaks down as 72 is the single-row dimension series (medium-duty 7200 single-row family); 15 encodes the 75 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). On speed, the grease limiting speed is 4,500 r/min and the oil rating 6,000 r/min. For a 75 mm shaft with combined load, the practical shortlist is this series, its 7300-series heavier section, and — where thrust reverses — a back-to-back pair rather than a single row. Grease quantity matters as much as grade at 4,500 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 75 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7215B without re-checking axial float, heat and housing width — the kinematics differ.",
      "Grease rated for deep-groove motor duty is not automatically right at 4,500 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The C0 of 62 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 79/62 kN ratings and 4.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7215B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7215B?",
        "a": "7215B is a single-row angular contact ball bearing to ISO 15: 75 mm bore, 130 mm outside diameter, 25 mm width (2.953 x 5.118 x 0.984 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 79 kN, C0 62 kN and a 4.5 kN fatigue load limit Pu; the grease limiting speed is 4,500 r/min and the oil rating 6,000 r/min; mass about 1190 g."
      },
      {
        "q": "How is the 7215B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 15 encodes the 75 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 130 mm OD and 25 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7215B support?",
        "a": "One 7215B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7215B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,500 r/min and the oil rating 6,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7215B?",
        "a": "The 75/130/25 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 79 kN / C0 62 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7215B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7215b",
      "7215B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ215",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ215",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 75,
    "D_mm": 130,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 106,
    "static_load_kN": 183,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 7.55,
    "limiting_speed_rpm": 3800,
    "max_rpm": 3800,
    "speed_oil_rpm": 5000,
    "weight_g": 1530,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 75 x 130 x 25 mm, NTN QJ215 sits in the medium-duty QJ200 four-point family of the angular-contact programme. Decoding QJ215: QJ2 is the four-point dimension series (medium-duty QJ200 four-point family), with the last two digits 15 give the bore by the standard code table (75 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. At roughly 27.5 mm of radial section, the catalogue still quotes 106 kN dynamic capacity for the 75 mm bore. Against a deep-groove bearing of the same 75 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. A 75 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "Bearings of 75 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single QJ215 without re-checking axial float, heat and housing width — the kinematics differ.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 106/183 kN ratings and 7.55 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ215; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ215?",
        "a": "QJ215 is a four-point contact ball bearing to ISO 15: 75 mm bore, 130 mm outside diameter, 25 mm width (2.953 x 5.118 x 0.984 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 106 kN, C0 183 kN and a 7.55 kN fatigue load limit Pu; the grease limiting speed is 3,800 r/min and the oil rating 5,000 r/min; mass about 1530 g."
      },
      {
        "q": "How is the QJ215 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 15 give the bore by the standard code table (75 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 130 mm OD and 25 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ215 support?",
        "a": "QJ215 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ215?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,800 r/min and the oil rating 5,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ215?",
        "a": "The 75/130/25 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 106 kN / C0 183 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ215",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj215",
      "QJ215"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7315-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7315",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 75,
    "D_mm": 160,
    "B_mm": 37,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 150,
    "static_load_kN": 106,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 7.65,
    "limiting_speed_rpm": 4800,
    "max_rpm": 4800,
    "speed_oil_rpm": 6300,
    "weight_g": 3070,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7315 is the 75 mm bore member of NTN's heavy-duty 7300 single-row family, with a 160 mm outside diameter and 37 mm section width. NTN builds the number from 73 is the single-row dimension series (heavy-duty 7300 single-row family), then 15 encodes the 75 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 30 deg contact angle is the lever that turns the 106 kN static rating into useful one-direction thrust capacity. Choose the heavy-duty 7300 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 75 mm bore give the working limits. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 75 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The C0 of 106 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "A 7315 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 150/106 kN ratings and 7.65 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7315; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7315?",
        "a": "7315 is a single-row angular contact ball bearing to ISO 15: 75 mm bore, 160 mm outside diameter, 37 mm width (2.953 x 6.299 x 1.457 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 150 kN, C0 106 kN and a 7.65 kN fatigue load limit Pu; the grease limiting speed is 4,800 r/min and the oil rating 6,300 r/min; mass about 3070 g."
      },
      {
        "q": "How is the 7315 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 15 encodes the 75 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 160 mm OD and 37 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7315 support?",
        "a": "One 7315 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7315?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,800 r/min and the oil rating 6,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7315?",
        "a": "The 75/160/37 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 150 kN / C0 106 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7315",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×160×37 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7315-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×160×37 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7315-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×160×37 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7315-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×160×37 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7315-BEGAPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×160×37 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7315-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×160×37 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7315",
      "7315-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7315B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7315B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 75,
    "D_mm": 160,
    "B_mm": 37,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 138,
    "static_load_kN": 97.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 7,
    "limiting_speed_rpm": 4100,
    "max_rpm": 4100,
    "speed_oil_rpm": 5400,
    "weight_g": 3130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 75 x 160 x 37 mm, NTN 7315B sits in the heavy-duty 7300 single-row family of the angular-contact programme. Decoding 7315B: 73 is the single-row dimension series (heavy-duty 7300 single-row family), with 15 encodes the 75 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The static margin, C0 97.5 kN versus C 138 kN, is what supports slow oscillating duty and shock without immediate brinelling. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 75 mm bore give the working limits. ",
    "applications": [
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "Bearings of 75 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Grease rated for deep-groove motor duty is not automatically right at 4,100 r/min with preload; check the grease speed factor against the catalogue figure.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Do not pair two random 7315B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 138/97.5 kN ratings and 7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7315B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7315B?",
        "a": "7315B is a single-row angular contact ball bearing to ISO 15: 75 mm bore, 160 mm outside diameter, 37 mm width (2.953 x 6.299 x 1.457 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 138 kN, C0 97.5 kN and a 7 kN fatigue load limit Pu; the grease limiting speed is 4,100 r/min and the oil rating 5,400 r/min; mass about 3130 g."
      },
      {
        "q": "How is the 7315B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 15 encodes the 75 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 160 mm OD and 37 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7315B support?",
        "a": "One 7315B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7315B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,100 r/min and the oil rating 5,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7315B?",
        "a": "The 75/160/37 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 138 kN / C0 97.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7315B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7315b",
      "7315B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ315",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ315",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 75,
    "D_mm": 160,
    "B_mm": 37,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 187,
    "static_load_kN": 294,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 11.7,
    "limiting_speed_rpm": 3400,
    "max_rpm": 3400,
    "speed_oil_rpm": 4500,
    "weight_g": 3900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty QJ300 four-point family, QJ315 measures 75 mm across the bore, 160 mm over the outer ring and 37 mm across the faces. Two fields make up the code — QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family) and the last two digits 15 give the bore by the standard code table (75 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. Catalogue mass is about 3900 g, which at this 42.5 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. A 75 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 75 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 187/294 kN ratings and 11.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ315; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ315?",
        "a": "QJ315 is a four-point contact ball bearing to ISO 15: 75 mm bore, 160 mm outside diameter, 37 mm width (2.953 x 6.299 x 1.457 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 187 kN, C0 294 kN and a 11.7 kN fatigue load limit Pu; the grease limiting speed is 3,400 r/min and the oil rating 4,500 r/min; mass about 3900 g."
      },
      {
        "q": "How is the QJ315 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 15 give the bore by the standard code table (75 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 160 mm OD and 37 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ315 support?",
        "a": "QJ315 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ315?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,400 r/min and the oil rating 4,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ315?",
        "a": "The 75/160/37 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 187 kN / C0 294 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ315",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj315",
      "QJ315"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7916",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7916",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 80,
    "D_mm": 110,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 29.8,
    "static_load_kN": 28,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 1.86,
    "limiting_speed_rpm": 5900,
    "max_rpm": 5900,
    "speed_oil_rpm": 7800,
    "weight_g": 444,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7916 appears as a extra-light, high-speed 7900 single-row family bearing of 80 mm bore, 110 mm outside diameter and 16 mm width. NTN builds the number from 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), then 16 encodes the 80 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The static margin, C0 28 kN versus C 29.8 kN, is what supports slow oscillating duty and shock without immediate brinelling. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Grease quantity matters as much as grade at 5,900 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 80 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 28 kN really covers the worst static case before substituting it for a 7000.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Do not pair two random 7916 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 29.8/28 kN ratings and 1.86 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7916; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7916?",
        "a": "7916 is a single-row angular contact ball bearing to ISO 15: 80 mm bore, 110 mm outside diameter, 16 mm width (3.15 x 4.331 x 0.63 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 29.8 kN, C0 28 kN and a 1.86 kN fatigue load limit Pu; the grease limiting speed is 5,900 r/min and the oil rating 7,800 r/min; mass about 444 g."
      },
      {
        "q": "How is the 7916 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 16 encodes the 80 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 110 mm OD and 16 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7916 support?",
        "a": "One 7916 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7916?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,900 r/min and the oil rating 7,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7916?",
        "a": "The 80/110/16 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 29.8 kN / C0 28 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7916",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7916"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7016-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7016",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 80,
    "D_mm": 125,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 59,
    "static_load_kN": 50.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 3.5,
    "limiting_speed_rpm": 5500,
    "max_rpm": 5500,
    "speed_oil_rpm": 7300,
    "weight_g": 994,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7016 is the 80 mm bore member of NTN's standard-section 7000 single-row family, with a 125 mm outside diameter and 22 mm section width. NTN builds the number from 70 is the single-row dimension series (standard-section 7000 single-row family), then 16 encodes the 80 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. With C 59 kN and C0 50.5 kN, each mm of bore carries about 0.74 kN of dynamic rating. For a 80 mm shaft with combined load, the practical shortlist is this series, its 7300-series heavier section, and — where thrust reverses — a back-to-back pair rather than a single row. Heat-mounting to 80-90 deg C is the clean route onto a 80 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 80 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "A 7016 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "On a 80 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 59/50.5 kN ratings and 3.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7016; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7016?",
        "a": "7016 is a single-row angular contact ball bearing to ISO 15: 80 mm bore, 125 mm outside diameter, 22 mm width (3.15 x 4.921 x 0.866 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 59 kN, C0 50.5 kN and a 3.5 kN fatigue load limit Pu; the grease limiting speed is 5,500 r/min and the oil rating 7,300 r/min; mass about 994 g."
      },
      {
        "q": "How is the 7016 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 16 encodes the 80 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 125 mm OD and 22 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7016 support?",
        "a": "One 7016 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7016?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,500 r/min and the oil rating 7,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7016?",
        "a": "The 80/125/22 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 59 kN / C0 50.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7016",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7016",
      "7016-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5216S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5216S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 80,
    "D_mm": 140,
    "B_mm": 44.4,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 99,
    "static_load_kN": 93,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 5.7,
    "limiting_speed_rpm": 3000,
    "max_rpm": 3000,
    "speed_oil_rpm": 3800,
    "weight_g": 2510,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "5216S is the 80 mm bore member of NTN's medium-duty 5200S double-row family, with a 140 mm outside diameter and 44.4 mm section width. The designation breaks down as 52 is the double-row dimension series (medium-duty 5200S double-row family); 16 encodes the 80 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. At roughly 30.0 mm of radial section, the catalogue still quotes 99 kN dynamic capacity for the 80 mm bore. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Grease quantity matters as much as grade at 3,000 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 80 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Grease rated for deep-groove motor duty is not automatically right at 3,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 99/93 kN ratings and 5.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5216S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5216S?",
        "a": "5216S is a double-row angular contact ball bearing to ISO 15: 80 mm bore, 140 mm outside diameter, 44.4 mm width (3.15 x 5.512 x 1.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 99 kN, C0 93 kN and a 5.7 kN fatigue load limit Pu; the grease limiting speed is 3,000 r/min and the oil rating 3,800 r/min; mass about 2510 g."
      },
      {
        "q": "How is the 5216S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 16 encodes the 80 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 140 mm OD and 44.4 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5216S support?",
        "a": "5216S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5216S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,000 r/min and the oil rating 3,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5216S?",
        "a": "The 80/140/44.4 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 99 kN / C0 93 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5216S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5216s",
      "5216S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7216-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7216",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 80,
    "D_mm": 140,
    "B_mm": 26,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 98.5,
    "static_load_kN": 76,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 5.65,
    "limiting_speed_rpm": 5000,
    "max_rpm": 5000,
    "speed_oil_rpm": 6600,
    "weight_g": 1390,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7216 is the 80 mm bore member of NTN's medium-duty 7200 single-row family, with a 140 mm outside diameter and 26 mm section width. Two fields make up the code — 72 is the single-row dimension series (medium-duty 7200 single-row family) and 16 encodes the 80 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The static margin, C0 76 kN versus C 98.5 kN, is what supports slow oscillating duty and shock without immediate brinelling. The 80/140/26 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 80 mm bore give the working limits. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 80 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "On a 80 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "On a 80 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Do not pair two random 7216 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 98.5/76 kN ratings and 5.65 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7216; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7216?",
        "a": "7216 is a single-row angular contact ball bearing to ISO 15: 80 mm bore, 140 mm outside diameter, 26 mm width (3.15 x 5.512 x 1.024 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 98.5 kN, C0 76 kN and a 5.65 kN fatigue load limit Pu; the grease limiting speed is 5,000 r/min and the oil rating 6,600 r/min; mass about 1390 g."
      },
      {
        "q": "How is the 7216 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 16 encodes the 80 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 140 mm OD and 26 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7216 support?",
        "a": "One 7216 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7216?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,000 r/min and the oil rating 6,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7216?",
        "a": "The 80/140/26 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 98.5 kN / C0 76 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7216",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7216-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7216-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7216-BECBPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7216-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7216-BEGAPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7216-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7216",
      "7216-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7216B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7216B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 80,
    "D_mm": 140,
    "B_mm": 26,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 89,
    "static_load_kN": 69.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 4.9,
    "limiting_speed_rpm": 4300,
    "max_rpm": 4300,
    "speed_oil_rpm": 5700,
    "weight_g": 1420,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7216B belongs to the medium-duty 7200 single-row family: the catalogue boundary dimensions read 80 / 140 / 26 mm (bore / OD / width). Two fields make up the code — 72 is the single-row dimension series (medium-duty 7200 single-row family) and 16 encodes the 80 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The static margin, C0 69.5 kN versus C 89 kN, is what supports slow oscillating duty and shock without immediate brinelling. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 80 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7216B without re-checking axial float, heat and housing width — the kinematics differ.",
      "Do not pair two random 7216B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 89/69.5 kN ratings and 4.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7216B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7216B?",
        "a": "7216B is a single-row angular contact ball bearing to ISO 15: 80 mm bore, 140 mm outside diameter, 26 mm width (3.15 x 5.512 x 1.024 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 89 kN, C0 69.5 kN and a 4.9 kN fatigue load limit Pu; the grease limiting speed is 4,300 r/min and the oil rating 5,700 r/min; mass about 1420 g."
      },
      {
        "q": "How is the 7216B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 16 encodes the 80 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 140 mm OD and 26 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7216B support?",
        "a": "One 7216B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7216B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,300 r/min and the oil rating 5,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7216B?",
        "a": "The 80/140/26 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 89 kN / C0 69.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7216B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7216b",
      "7216B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ216",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ216",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 80,
    "D_mm": 140,
    "B_mm": 26,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 124,
    "static_load_kN": 217,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 8.65,
    "limiting_speed_rpm": 3500,
    "max_rpm": 3500,
    "speed_oil_rpm": 4700,
    "weight_g": 1830,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "QJ216 is the 80 mm bore member of NTN's medium-duty QJ200 four-point family, with a 140 mm outside diameter and 26 mm section width. NTN builds the number from QJ2 is the four-point dimension series (medium-duty QJ200 four-point family), then the last two digits 16 give the bore by the standard code table (80 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. NTN prints 124 kN dynamic and 217 kN static for this size and a 8.65 kN fatigue load limit Pu. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 80 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "The C0 of 217 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single QJ216 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 124/217 kN ratings and 8.65 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ216; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ216?",
        "a": "QJ216 is a four-point contact ball bearing to ISO 15: 80 mm bore, 140 mm outside diameter, 26 mm width (3.15 x 5.512 x 1.024 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 124 kN, C0 217 kN and a 8.65 kN fatigue load limit Pu; the grease limiting speed is 3,500 r/min and the oil rating 4,700 r/min; mass about 1830 g."
      },
      {
        "q": "How is the QJ216 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 16 give the bore by the standard code table (80 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 140 mm OD and 26 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ216 support?",
        "a": "QJ216 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ216?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,500 r/min and the oil rating 4,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ216?",
        "a": "The 80/140/26 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 124 kN / C0 217 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ216",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj216",
      "QJ216"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7316-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7316",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 80,
    "D_mm": 170,
    "B_mm": 39,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 163,
    "static_load_kN": 119,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 8.3,
    "limiting_speed_rpm": 4500,
    "max_rpm": 4500,
    "speed_oil_rpm": 5900,
    "weight_g": 3650,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty 7300 single-row family, 7316 measures 80 mm across the bore, 170 mm over the outer ring and 39 mm across the faces. Reading the code: 73 is the single-row dimension series (heavy-duty 7300 single-row family), 16 encodes the 80 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. On speed, the grease limiting speed is 4,500 r/min and the oil rating 5,900 r/min. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 80 mm bore give the working limits. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 80 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The C0 of 119 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 163/119 kN ratings and 8.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7316; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7316?",
        "a": "7316 is a single-row angular contact ball bearing to ISO 15: 80 mm bore, 170 mm outside diameter, 39 mm width (3.15 x 6.693 x 1.535 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 163 kN, C0 119 kN and a 8.3 kN fatigue load limit Pu; the grease limiting speed is 4,500 r/min and the oil rating 5,900 r/min; mass about 3650 g."
      },
      {
        "q": "How is the 7316 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 16 encodes the 80 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 170 mm OD and 39 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7316 support?",
        "a": "One 7316 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7316?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,500 r/min and the oil rating 5,900 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7316?",
        "a": "The 80/170/39 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 163 kN / C0 119 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7316",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×170×39 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7316-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×170×39 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7316-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×170×39 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7316-BECBPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×170×39 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7316-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×170×39 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7316-BEM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×170×39 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7316-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×170×39 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7316",
      "7316-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7316B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7316B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 80,
    "D_mm": 170,
    "B_mm": 39,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 149,
    "static_load_kN": 109,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 7.65,
    "limiting_speed_rpm": 3800,
    "max_rpm": 3800,
    "speed_oil_rpm": 5100,
    "weight_g": 3720,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7316B is an NTN single-row angular contact ball bearing: heavy-duty 7300 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 80 x 170 x 39 mm. The designation breaks down as 73 is the single-row dimension series (heavy-duty 7300 single-row family); 16 encodes the 80 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Catalogue dynamic rating C is 149 kN against C0 109 kN — a C0/C ratio of 0.73 that is typical of an angular-contact contact ellipse. The 80/170/39 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 80 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "On a 80 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "On a 80 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 149/109 kN ratings and 7.65 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7316B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7316B?",
        "a": "7316B is a single-row angular contact ball bearing to ISO 15: 80 mm bore, 170 mm outside diameter, 39 mm width (3.15 x 6.693 x 1.535 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 149 kN, C0 109 kN and a 7.65 kN fatigue load limit Pu; the grease limiting speed is 3,800 r/min and the oil rating 5,100 r/min; mass about 3720 g."
      },
      {
        "q": "How is the 7316B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 16 encodes the 80 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 170 mm OD and 39 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7316B support?",
        "a": "One 7316B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7316B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,800 r/min and the oil rating 5,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7316B?",
        "a": "The 80/170/39 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 149 kN / C0 109 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7316B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7316b",
      "7316B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ316",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ316",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 80,
    "D_mm": 170,
    "B_mm": 39,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 202,
    "static_load_kN": 330,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 12.7,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "speed_oil_rpm": 4200,
    "weight_g": 4640,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "QJ316 is an NTN four-point contact ball bearing: heavy-duty QJ300 four-point family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 80 x 170 x 39 mm. Decoding QJ316: QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family), with the last two digits 16 give the bore by the standard code table (80 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The radial section height here is 45.0 mm, and the catalogue couples that with C 202 kN / C0 330 kN. For a 80 mm shaft with combined load, the practical shortlist is this series, its neighbouring dimension series, and — where thrust reverses — a back-to-back pair rather than a single row. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "Bearings of 80 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Grease rated for deep-groove motor duty is not automatically right at 3,200 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Do not pair two random QJ316 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 202/330 kN ratings and 12.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ316; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ316?",
        "a": "QJ316 is a four-point contact ball bearing to ISO 15: 80 mm bore, 170 mm outside diameter, 39 mm width (3.15 x 6.693 x 1.535 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 202 kN, C0 330 kN and a 12.7 kN fatigue load limit Pu; the grease limiting speed is 3,200 r/min and the oil rating 4,200 r/min; mass about 4640 g."
      },
      {
        "q": "How is the QJ316 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 16 give the bore by the standard code table (80 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 170 mm OD and 39 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ316 support?",
        "a": "QJ316 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ316?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,200 r/min and the oil rating 4,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ316?",
        "a": "The 80/170/39 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 202 kN / C0 330 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ316",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj316",
      "QJ316"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7917",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7917",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 85,
    "D_mm": 120,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 40,
    "static_load_kN": 38,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 2.49,
    "limiting_speed_rpm": 5500,
    "max_rpm": 5500,
    "speed_oil_rpm": 7400,
    "weight_g": 628,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7917 belongs to the extra-light, high-speed 7900 single-row family: the catalogue boundary dimensions read 85 / 120 / 18 mm (bore / OD / width). The designation breaks down as 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 17 encodes the 85 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The oil rating of 7,400 r/min sits 1,900 r/min above the 5,500 r/min grease figure — a 1.35x step that says how much headroom oil cooling buys. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 85 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 38 kN really covers the worst static case before substituting it for a 7000.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "On a 85 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Grease rated for deep-groove motor duty is not automatically right at 5,500 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 40/38 kN ratings and 2.49 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7917; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7917?",
        "a": "7917 is a single-row angular contact ball bearing to ISO 15: 85 mm bore, 120 mm outside diameter, 18 mm width (3.346 x 4.724 x 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 40 kN, C0 38 kN and a 2.49 kN fatigue load limit Pu; the grease limiting speed is 5,500 r/min and the oil rating 7,400 r/min; mass about 628 g."
      },
      {
        "q": "How is the 7917 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 17 encodes the 85 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 120 mm OD and 18 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7917 support?",
        "a": "One 7917 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7917?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,500 r/min and the oil rating 7,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7917?",
        "a": "The 85/120/18 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 40 kN / C0 38 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7917",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7917"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7017-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7017",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 85,
    "D_mm": 130,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 60.5,
    "static_load_kN": 53.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 3.6,
    "limiting_speed_rpm": 5100,
    "max_rpm": 5100,
    "speed_oil_rpm": 6900,
    "weight_g": 1040,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 85 x 130 x 22 mm, NTN 7017 sits in the standard-section 7000 single-row family of the angular-contact programme. Reading the code: 70 is the single-row dimension series (standard-section 7000 single-row family), 17 encodes the 85 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Against a deep-groove bearing of the same 85 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 85 mm bore give the working limits. ",
    "applications": [
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 85 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The C0 of 53.5 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 5,100 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 60.5/53.5 kN ratings and 3.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7017; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7017?",
        "a": "7017 is a single-row angular contact ball bearing to ISO 15: 85 mm bore, 130 mm outside diameter, 22 mm width (3.346 x 5.118 x 0.866 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 60.5 kN, C0 53.5 kN and a 3.6 kN fatigue load limit Pu; the grease limiting speed is 5,100 r/min and the oil rating 6,900 r/min; mass about 1040 g."
      },
      {
        "q": "How is the 7017 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 17 encodes the 85 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 130 mm OD and 22 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7017 support?",
        "a": "One 7017 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7017?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,100 r/min and the oil rating 6,900 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7017?",
        "a": "The 85/130/22 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 60.5 kN / C0 53.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7017",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7017",
      "7017-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "5217S",
    "brand": "NTN",
    "manufacturer_designation": "NTN 5217S",
    "series": "5200S-series",
    "type": "angular_contact",
    "d_mm": 85,
    "D_mm": 150,
    "B_mm": 49.2,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 116,
    "static_load_kN": 110,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 6.7,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "speed_oil_rpm": 3600,
    "weight_g": 3160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 5217S appears as a medium-duty 5200S double-row family bearing of 85 mm bore, 150 mm outside diameter and 49.2 mm width. Two fields make up the code — 52 is the double-row dimension series (medium-duty 5200S double-row family) and 17 encodes the 85 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Choose the medium-duty 5200S double-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 85 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The double-row bearing takes reversing thrust in one envelope, but its two contact lines mean more heat than a single row at the same speed — check the thermal balance before copying a single-row speed figure.",
      "The 2,800 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 5217S without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 2,800 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 116/110 kN ratings and 6.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 5217S; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 5217S?",
        "a": "5217S is a double-row angular contact ball bearing to ISO 15: 85 mm bore, 150 mm outside diameter, 49.2 mm width (3.346 x 5.906 x 1.937 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 116 kN, C0 110 kN and a 6.7 kN fatigue load limit Pu; the grease limiting speed is 2,800 r/min and the oil rating 3,600 r/min; mass about 3160 g."
      },
      {
        "q": "How is the 5217S designation structured?",
        "a": "52 is the double-row dimension series (medium-duty 5200S double-row family); 17 encodes the 85 mm bore (bore code x 5), and the trailing S marks the current internal design of the family. The 150 mm OD and 49.2 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 5217S support?",
        "a": "5217S is a double-row bearing working like a built-in back-to-back pair: it takes thrust in both directions plus radial load and moment (tilting) load in a single envelope."
      },
      {
        "q": "What lubrication speeds does NTN print for 5217S?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,800 r/min and the oil rating 3,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 5217S?",
        "a": "The 85/150/49.2 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 116 kN / C0 110 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "5217S",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=135",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "5217s",
      "5217S"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7217-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7217",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 85,
    "D_mm": 150,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 110,
    "static_load_kN": 88.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 6.25,
    "limiting_speed_rpm": 4700,
    "max_rpm": 4700,
    "speed_oil_rpm": 6200,
    "weight_g": 1780,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 7200 single-row family, 7217 measures 85 mm across the bore, 150 mm over the outer ring and 28 mm across the faces. Reading the code: 72 is the single-row dimension series (medium-duty 7200 single-row family), 17 encodes the 85 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The oil rating of 6,200 r/min sits 1,500 r/min above the 4,700 r/min grease figure — a 1.32x step that says how much headroom oil cooling buys. Size selection is usually finished by checking that the C0 of 88.5 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 85 mm bore give the working limits. ",
    "applications": [
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 85 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "A 7217 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Grease rated for deep-groove motor duty is not automatically right at 4,700 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 110/88.5 kN ratings and 6.25 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7217; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7217?",
        "a": "7217 is a single-row angular contact ball bearing to ISO 15: 85 mm bore, 150 mm outside diameter, 28 mm width (3.346 x 5.906 x 1.102 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 110 kN, C0 88.5 kN and a 6.25 kN fatigue load limit Pu; the grease limiting speed is 4,700 r/min and the oil rating 6,200 r/min; mass about 1780 g."
      },
      {
        "q": "How is the 7217 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 17 encodes the 85 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 150 mm OD and 28 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7217 support?",
        "a": "One 7217 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7217?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,700 r/min and the oil rating 6,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7217?",
        "a": "The 85/150/28 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 110 kN / C0 88.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7217",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 85×150×28 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7217-BECBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7217-BECBP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7217-BECBY",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7217-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 85×150×28 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7217",
      "7217-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7217B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7217B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 85,
    "D_mm": 150,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 99.5,
    "static_load_kN": 80.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 5.45,
    "limiting_speed_rpm": 4000,
    "max_rpm": 4000,
    "speed_oil_rpm": 5300,
    "weight_g": 1820,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7217B is the 85 mm bore member of NTN's medium-duty 7200 single-row family, with a 150 mm outside diameter and 28 mm section width. NTN builds the number from 72 is the single-row dimension series (medium-duty 7200 single-row family), then 17 encodes the 85 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Catalogue dynamic rating C is 99.5 kN against C0 80.5 kN — a C0/C ratio of 0.81 that is typical of an angular-contact contact ellipse. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Heat-mounting to 80-90 deg C is the clean route onto a 85 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 85 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Do not pair two random 7217B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 99.5/80.5 kN ratings and 5.45 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7217B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7217B?",
        "a": "7217B is a single-row angular contact ball bearing to ISO 15: 85 mm bore, 150 mm outside diameter, 28 mm width (3.346 x 5.906 x 1.102 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 99.5 kN, C0 80.5 kN and a 5.45 kN fatigue load limit Pu; the grease limiting speed is 4,000 r/min and the oil rating 5,300 r/min; mass about 1820 g."
      },
      {
        "q": "How is the 7217B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 17 encodes the 85 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 150 mm OD and 28 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7217B support?",
        "a": "One 7217B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7217B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,000 r/min and the oil rating 5,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7217B?",
        "a": "The 85/150/28 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 99.5 kN / C0 80.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7217B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=130",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7217b",
      "7217B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ217",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ217",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 85,
    "D_mm": 150,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 139,
    "static_load_kN": 252,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 9.65,
    "limiting_speed_rpm": 3300,
    "max_rpm": 3300,
    "speed_oil_rpm": 4400,
    "weight_g": 2300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty QJ200 four-point family, QJ217 measures 85 mm across the bore, 150 mm over the outer ring and 28 mm across the faces. The designation breaks down as QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 17 give the bore by the standard code table (85 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. The 85/150/28 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 85 mm bore give the working limits. ",
    "applications": [
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 85 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Do not pair two random QJ217 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 3,300 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 139/252 kN ratings and 9.65 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ217; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ217?",
        "a": "QJ217 is a four-point contact ball bearing to ISO 15: 85 mm bore, 150 mm outside diameter, 28 mm width (3.346 x 5.906 x 1.102 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 139 kN, C0 252 kN and a 9.65 kN fatigue load limit Pu; the grease limiting speed is 3,300 r/min and the oil rating 4,400 r/min; mass about 2300 g."
      },
      {
        "q": "How is the QJ217 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 17 give the bore by the standard code table (85 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 150 mm OD and 28 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ217 support?",
        "a": "QJ217 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ217?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,300 r/min and the oil rating 4,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ217?",
        "a": "The 85/150/28 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 139 kN / C0 252 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ217",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj217",
      "QJ217"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7317-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7317",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 85,
    "D_mm": 180,
    "B_mm": 41,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 176,
    "static_load_kN": 133,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 9,
    "limiting_speed_rpm": 4200,
    "max_rpm": 4200,
    "speed_oil_rpm": 5600,
    "weight_g": 4340,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7317 is the 85 mm bore member of NTN's heavy-duty 7300 single-row family, with a 180 mm outside diameter and 41 mm section width. The designation breaks down as 73 is the single-row dimension series (heavy-duty 7300 single-row family); 17 encodes the 85 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The static margin, C0 133 kN versus C 176 kN, is what supports slow oscillating duty and shock without immediate brinelling. Choose the heavy-duty 7300 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 85 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 4,200 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Do not pair two random 7317 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 176/133 kN ratings and 9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7317; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7317?",
        "a": "7317 is a single-row angular contact ball bearing to ISO 15: 85 mm bore, 180 mm outside diameter, 41 mm width (3.346 x 7.087 x 1.614 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 176 kN, C0 133 kN and a 9 kN fatigue load limit Pu; the grease limiting speed is 4,200 r/min and the oil rating 5,600 r/min; mass about 4340 g."
      },
      {
        "q": "How is the 7317 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 17 encodes the 85 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 180 mm OD and 41 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7317 support?",
        "a": "One 7317 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7317?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,200 r/min and the oil rating 5,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7317?",
        "a": "The 85/180/41 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 176 kN / C0 133 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7317",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 85×180×41 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7317-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 85×180×41 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7317-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 85×180×41 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7317-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 85×180×41 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7317-BEGAPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 85×180×41 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7317-BEM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 85×180×41 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7317-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 85×180×41 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7317",
      "7317-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7317B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7317B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 85,
    "D_mm": 180,
    "B_mm": 41,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 161,
    "static_load_kN": 122,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 8.3,
    "limiting_speed_rpm": 3600,
    "max_rpm": 3600,
    "speed_oil_rpm": 4800,
    "weight_g": 4430,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The heavy-duty 7300 single-row family entry 7317B carries a 85 mm bore in a 180 mm outside diameter, 41 mm wide envelope. Two fields make up the code — 73 is the single-row dimension series (heavy-duty 7300 single-row family) and 17 encodes the 85 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). NTN prints 161 kN dynamic and 122 kN static for this size and a 8.3 kN fatigue load limit Pu. Size selection is usually finished by checking that the C0 of 122 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. A 85 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 85 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "A 7317B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7317B without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 161/122 kN ratings and 8.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7317B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7317B?",
        "a": "7317B is a single-row angular contact ball bearing to ISO 15: 85 mm bore, 180 mm outside diameter, 41 mm width (3.346 x 7.087 x 1.614 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 161 kN, C0 122 kN and a 8.3 kN fatigue load limit Pu; the grease limiting speed is 3,600 r/min and the oil rating 4,800 r/min; mass about 4430 g."
      },
      {
        "q": "How is the 7317B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 17 encodes the 85 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 180 mm OD and 41 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7317B support?",
        "a": "One 7317B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7317B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,600 r/min and the oil rating 4,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7317B?",
        "a": "The 85/180/41 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 161 kN / C0 122 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7317B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7317b",
      "7317B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ317",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ317",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 85,
    "D_mm": 180,
    "B_mm": 41,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 218,
    "static_load_kN": 370,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 13.8,
    "limiting_speed_rpm": 3000,
    "max_rpm": 3000,
    "speed_oil_rpm": 4000,
    "weight_g": 5430,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, QJ317 appears as a heavy-duty QJ300 four-point family bearing of 85 mm bore, 180 mm outside diameter and 41 mm width. NTN builds the number from QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family), then the last two digits 17 give the bore by the standard code table (85 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 35 deg four-point geometry doubles the axial contact points, so the 218 kN rating is available for thrust in both directions. Against a deep-groove bearing of the same 85 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 85 mm bore give the working limits. ",
    "applications": [
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 85 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "A QJ317 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "A QJ317 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 218/370 kN ratings and 13.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ317; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ317?",
        "a": "QJ317 is a four-point contact ball bearing to ISO 15: 85 mm bore, 180 mm outside diameter, 41 mm width (3.346 x 7.087 x 1.614 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 218 kN, C0 370 kN and a 13.8 kN fatigue load limit Pu; the grease limiting speed is 3,000 r/min and the oil rating 4,000 r/min; mass about 5430 g."
      },
      {
        "q": "How is the QJ317 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 17 give the bore by the standard code table (85 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 180 mm OD and 41 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ317 support?",
        "a": "QJ317 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ317?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,000 r/min and the oil rating 4,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ317?",
        "a": "The 85/180/41 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 218 kN / C0 370 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ317",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj317",
      "QJ317"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7918",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7918",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 90,
    "D_mm": 125,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 39.5,
    "static_load_kN": 38,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 2.42,
    "limiting_speed_rpm": 5200,
    "max_rpm": 5200,
    "speed_oil_rpm": 7000,
    "weight_g": 658,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The extra-light, high-speed 7900 single-row family entry 7918 carries a 90 mm bore in a 125 mm outside diameter, 18 mm wide envelope. Reading the code: 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), 18 encodes the 90 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue dynamic rating C is 39.5 kN against C0 38 kN — a C0/C ratio of 0.96 that is typical of an angular-contact contact ellipse. Choose the extra-light, high-speed 7900 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. A 90 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 90 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 38 kN really covers the worst static case before substituting it for a 7000.",
      "Grease rated for deep-groove motor duty is not automatically right at 5,200 r/min with preload; check the grease speed factor against the catalogue figure.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 39.5/38 kN ratings and 2.42 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7918; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7918?",
        "a": "7918 is a single-row angular contact ball bearing to ISO 15: 90 mm bore, 125 mm outside diameter, 18 mm width (3.543 x 4.921 x 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 39.5 kN, C0 38 kN and a 2.42 kN fatigue load limit Pu; the grease limiting speed is 5,200 r/min and the oil rating 7,000 r/min; mass about 658 g."
      },
      {
        "q": "How is the 7918 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 18 encodes the 90 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 125 mm OD and 18 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7918 support?",
        "a": "One 7918 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7918?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,200 r/min and the oil rating 7,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7918?",
        "a": "The 90/125/18 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 39.5 kN / C0 38 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7918",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7918"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7018-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7018",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 90,
    "D_mm": 140,
    "B_mm": 24,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 72,
    "static_load_kN": 63.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 4.15,
    "limiting_speed_rpm": 4900,
    "max_rpm": 4900,
    "speed_oil_rpm": 6500,
    "weight_g": 1350,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7018 is the 90 mm bore member of NTN's standard-section 7000 single-row family, with a 140 mm outside diameter and 24 mm section width. The designation breaks down as 70 is the single-row dimension series (standard-section 7000 single-row family); 18 encodes the 90 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue mass is about 1350 g, which at this 25.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 90 mm bore give the working limits. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 90 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Grease rated for deep-groove motor duty is not automatically right at 4,900 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Grease rated for deep-groove motor duty is not automatically right at 4,900 r/min with preload; check the grease speed factor against the catalogue figure.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 72/63.5 kN ratings and 4.15 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7018; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7018?",
        "a": "7018 is a single-row angular contact ball bearing to ISO 15: 90 mm bore, 140 mm outside diameter, 24 mm width (3.543 x 5.512 x 0.945 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 72 kN, C0 63.5 kN and a 4.15 kN fatigue load limit Pu; the grease limiting speed is 4,900 r/min and the oil rating 6,500 r/min; mass about 1350 g."
      },
      {
        "q": "How is the 7018 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 18 encodes the 90 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 140 mm OD and 24 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7018 support?",
        "a": "One 7018 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7018?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,900 r/min and the oil rating 6,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7018?",
        "a": "The 90/140/24 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 72 kN / C0 63.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7018",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7018",
      "7018-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7218-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7218",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 90,
    "D_mm": 160,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 130,
    "static_load_kN": 103,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 7.2,
    "limiting_speed_rpm": 4400,
    "max_rpm": 4400,
    "speed_oil_rpm": 5900,
    "weight_g": 2180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7218 is the 90 mm bore member of NTN's medium-duty 7200 single-row family, with a 160 mm outside diameter and 30 mm section width. Decoding 7218: 72 is the single-row dimension series (medium-duty 7200 single-row family), with 18 encodes the 90 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. At roughly 35.0 mm of radial section, the catalogue still quotes 130 kN dynamic capacity for the 90 mm bore. The 90/160/30 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "Bearings of 90 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The C0 of 103 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 130/103 kN ratings and 7.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7218; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7218?",
        "a": "7218 is a single-row angular contact ball bearing to ISO 15: 90 mm bore, 160 mm outside diameter, 30 mm width (3.543 x 6.299 x 1.181 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 130 kN, C0 103 kN and a 7.2 kN fatigue load limit Pu; the grease limiting speed is 4,400 r/min and the oil rating 5,900 r/min; mass about 2180 g."
      },
      {
        "q": "How is the 7218 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 18 encodes the 90 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 160 mm OD and 30 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7218 support?",
        "a": "One 7218 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7218?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,400 r/min and the oil rating 5,900 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7218?",
        "a": "The 90/160/30 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 130 kN / C0 103 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7218",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×160×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7218-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×160×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7218-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×160×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7218-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×160×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7218-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×160×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7218",
      "7218-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7218B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7218B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 90,
    "D_mm": 160,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 118,
    "static_load_kN": 94,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 6.3,
    "limiting_speed_rpm": 3800,
    "max_rpm": 3800,
    "speed_oil_rpm": 5000,
    "weight_g": 2220,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7218B appears as a medium-duty 7200 single-row family bearing of 90 mm bore, 160 mm outside diameter and 30 mm width. Reading the code: 72 is the single-row dimension series (medium-duty 7200 single-row family), 18 encodes the 90 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). NTN prints 118 kN dynamic and 94 kN static for this size and a 6.3 kN fatigue load limit Pu. The 90/160/30 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 90 mm bore give the working limits. ",
    "applications": [
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 90 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "The C0 of 94 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "On a 90 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7218B without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 118/94 kN ratings and 6.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7218B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7218B?",
        "a": "7218B is a single-row angular contact ball bearing to ISO 15: 90 mm bore, 160 mm outside diameter, 30 mm width (3.543 x 6.299 x 1.181 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 118 kN, C0 94 kN and a 6.3 kN fatigue load limit Pu; the grease limiting speed is 3,800 r/min and the oil rating 5,000 r/min; mass about 2220 g."
      },
      {
        "q": "How is the 7218B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 18 encodes the 90 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 160 mm OD and 30 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7218B support?",
        "a": "One 7218B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7218B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,800 r/min and the oil rating 5,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7218B?",
        "a": "The 90/160/30 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 118 kN / C0 94 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7218B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7218b",
      "7218B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ218",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ218",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 90,
    "D_mm": 160,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 164,
    "static_load_kN": 293,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 11.1,
    "limiting_speed_rpm": 3100,
    "max_rpm": 3100,
    "speed_oil_rpm": 4200,
    "weight_g": 2760,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "QJ218 is an NTN four-point contact ball bearing: medium-duty QJ200 four-point family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 90 x 160 x 30 mm. Reading the code: QJ2 is the four-point dimension series (medium-duty QJ200 four-point family), the last two digits 18 give the bore by the standard code table (90 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. Catalogue mass is about 2760 g, which at this 35.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Heat-mounting to 80-90 deg C is the clean route onto a 90 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 90 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "A QJ218 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "A QJ218 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 164/293 kN ratings and 11.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ218; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ218?",
        "a": "QJ218 is a four-point contact ball bearing to ISO 15: 90 mm bore, 160 mm outside diameter, 30 mm width (3.543 x 6.299 x 1.181 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 164 kN, C0 293 kN and a 11.1 kN fatigue load limit Pu; the grease limiting speed is 3,100 r/min and the oil rating 4,200 r/min; mass about 2760 g."
      },
      {
        "q": "How is the QJ218 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 18 give the bore by the standard code table (90 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 160 mm OD and 30 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ218 support?",
        "a": "QJ218 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ218?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,100 r/min and the oil rating 4,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ218?",
        "a": "The 90/160/30 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 164 kN / C0 293 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ218",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj218",
      "QJ218"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7318-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7318",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 90,
    "D_mm": 190,
    "B_mm": 43,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 189,
    "static_load_kN": 147,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 9.7,
    "limiting_speed_rpm": 4000,
    "max_rpm": 4000,
    "speed_oil_rpm": 5300,
    "weight_g": 5060,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty 7300 single-row family, 7318 measures 90 mm across the bore, 190 mm over the outer ring and 43 mm across the faces. Two fields make up the code — 73 is the single-row dimension series (heavy-duty 7300 single-row family) and 18 encodes the 90 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The oil rating of 5,300 r/min sits 1,300 r/min above the 4,000 r/min grease figure — a 1.32x step that says how much headroom oil cooling buys. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 90 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Grease rated for deep-groove motor duty is not automatically right at 4,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 189/147 kN ratings and 9.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7318; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7318?",
        "a": "7318 is a single-row angular contact ball bearing to ISO 15: 90 mm bore, 190 mm outside diameter, 43 mm width (3.543 x 7.48 x 1.693 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 189 kN, C0 147 kN and a 9.7 kN fatigue load limit Pu; the grease limiting speed is 4,000 r/min and the oil rating 5,300 r/min; mass about 5060 g."
      },
      {
        "q": "How is the 7318 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 18 encodes the 90 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 190 mm OD and 43 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7318 support?",
        "a": "One 7318 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7318?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,000 r/min and the oil rating 5,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7318?",
        "a": "The 90/190/43 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 189 kN / C0 147 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7318",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×190×43 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7318-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×190×43 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7318-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×190×43 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7318-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×190×43 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7318-BEGAPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×190×43 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7318-BEM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×190×43 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7318-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×190×43 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7318",
      "7318-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7318B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7318B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 90,
    "D_mm": 190,
    "B_mm": 43,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 173,
    "static_load_kN": 135,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 8.95,
    "limiting_speed_rpm": 3400,
    "max_rpm": 3400,
    "speed_oil_rpm": 4500,
    "weight_g": 5160,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty 7300 single-row family, 7318B measures 90 mm across the bore, 190 mm over the outer ring and 43 mm across the faces. NTN builds the number from 73 is the single-row dimension series (heavy-duty 7300 single-row family), then 18 encodes the 90 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Catalogue mass is about 5160 g, which at this 50.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 90 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 3,400 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 173/135 kN ratings and 8.95 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7318B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7318B?",
        "a": "7318B is a single-row angular contact ball bearing to ISO 15: 90 mm bore, 190 mm outside diameter, 43 mm width (3.543 x 7.48 x 1.693 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 173 kN, C0 135 kN and a 8.95 kN fatigue load limit Pu; the grease limiting speed is 3,400 r/min and the oil rating 4,500 r/min; mass about 5160 g."
      },
      {
        "q": "How is the 7318B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 18 encodes the 90 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 190 mm OD and 43 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7318B support?",
        "a": "One 7318B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7318B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,400 r/min and the oil rating 4,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7318B?",
        "a": "The 90/190/43 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 173 kN / C0 135 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7318B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7318b",
      "7318B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ318",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ318",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 90,
    "D_mm": 190,
    "B_mm": 43,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 235,
    "static_load_kN": 410,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 14.8,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "speed_oil_rpm": 3800,
    "weight_g": 6310,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN QJ318 belongs to the heavy-duty QJ300 four-point family: the catalogue boundary dimensions read 90 / 190 / 43 mm (bore / OD / width). The designation breaks down as QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 18 give the bore by the standard code table (90 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. On speed, the grease limiting speed is 2,800 r/min and the oil rating 3,800 r/min. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Heat-mounting to 80-90 deg C is the clean route onto a 90 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 90 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Do not pair two random QJ318 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 2,800 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The C0 of 410 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 235/410 kN ratings and 14.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ318; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ318?",
        "a": "QJ318 is a four-point contact ball bearing to ISO 15: 90 mm bore, 190 mm outside diameter, 43 mm width (3.543 x 7.48 x 1.693 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 235 kN, C0 410 kN and a 14.8 kN fatigue load limit Pu; the grease limiting speed is 2,800 r/min and the oil rating 3,800 r/min; mass about 6310 g."
      },
      {
        "q": "How is the QJ318 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 18 give the bore by the standard code table (90 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 190 mm OD and 43 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ318 support?",
        "a": "QJ318 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ318?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,800 r/min and the oil rating 3,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ318?",
        "a": "The 90/190/43 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 235 kN / C0 410 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ318",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj318",
      "QJ318"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7919",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7919",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 95,
    "D_mm": 130,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 41.5,
    "static_load_kN": 40.5,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 2.54,
    "limiting_speed_rpm": 5000,
    "max_rpm": 5000,
    "speed_oil_rpm": 6600,
    "weight_g": 688,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 95 x 130 x 18 mm, NTN 7919 sits in the extra-light, high-speed 7900 single-row family of the angular-contact programme. Two fields make up the code — 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family) and 19 encodes the 95 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. At roughly 17.5 mm of radial section, the catalogue still quotes 41.5 kN dynamic capacity for the 95 mm bore. Size selection is usually finished by checking that the C0 of 40.5 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 95 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 40.5 kN really covers the worst static case before substituting it for a 7000.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7919 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 41.5/40.5 kN ratings and 2.54 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7919; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7919?",
        "a": "7919 is a single-row angular contact ball bearing to ISO 15: 95 mm bore, 130 mm outside diameter, 18 mm width (3.74 x 5.118 x 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 41.5 kN, C0 40.5 kN and a 2.54 kN fatigue load limit Pu; the grease limiting speed is 5,000 r/min and the oil rating 6,600 r/min; mass about 688 g."
      },
      {
        "q": "How is the 7919 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 19 encodes the 95 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 130 mm OD and 18 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7919 support?",
        "a": "One 7919 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7919?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 5,000 r/min and the oil rating 6,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7919?",
        "a": "The 95/130/18 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 41.5 kN / C0 40.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7919",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7919"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7019-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7019",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 95,
    "D_mm": 145,
    "B_mm": 24,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 74,
    "static_load_kN": 67,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 4.25,
    "limiting_speed_rpm": 4600,
    "max_rpm": 4600,
    "speed_oil_rpm": 6100,
    "weight_g": 1410,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the standard-section 7000 single-row family, 7019 measures 95 mm across the bore, 145 mm over the outer ring and 24 mm across the faces. Two fields make up the code — 70 is the single-row dimension series (standard-section 7000 single-row family) and 19 encodes the 95 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The radial section height here is 25.0 mm, and the catalogue couples that with C 74 kN / C0 67 kN. Against a deep-groove bearing of the same 95 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 95 mm bore give the working limits. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 95 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A 7019 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "On a 95 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 74/67 kN ratings and 4.25 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7019; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7019?",
        "a": "7019 is a single-row angular contact ball bearing to ISO 15: 95 mm bore, 145 mm outside diameter, 24 mm width (3.74 x 5.709 x 0.945 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 74 kN, C0 67 kN and a 4.25 kN fatigue load limit Pu; the grease limiting speed is 4,600 r/min and the oil rating 6,100 r/min; mass about 1410 g."
      },
      {
        "q": "How is the 7019 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 19 encodes the 95 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 145 mm OD and 24 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7019 support?",
        "a": "One 7019 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7019?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,600 r/min and the oil rating 6,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7019?",
        "a": "The 95/145/24 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 74 kN / C0 67 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7019",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7019",
      "7019-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7219-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7219",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 95,
    "D_mm": 170,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 148,
    "static_load_kN": 118,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 8.05,
    "limiting_speed_rpm": 4100,
    "max_rpm": 4100,
    "speed_oil_rpm": 5500,
    "weight_g": 2670,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 7200 single-row family, 7219 measures 95 mm across the bore, 170 mm over the outer ring and 32 mm across the faces. The designation breaks down as 72 is the single-row dimension series (medium-duty 7200 single-row family); 19 encodes the 95 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. NTN prints 148 kN dynamic and 118 kN static for this size and a 8.05 kN fatigue load limit Pu. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 95 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The 4,100 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7219 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7219 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 148/118 kN ratings and 8.05 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7219; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7219?",
        "a": "7219 is a single-row angular contact ball bearing to ISO 15: 95 mm bore, 170 mm outside diameter, 32 mm width (3.74 x 6.693 x 1.26 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 148 kN, C0 118 kN and a 8.05 kN fatigue load limit Pu; the grease limiting speed is 4,100 r/min and the oil rating 5,500 r/min; mass about 2670 g."
      },
      {
        "q": "How is the 7219 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 19 encodes the 95 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 170 mm OD and 32 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7219 support?",
        "a": "One 7219 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7219?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,100 r/min and the oil rating 5,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7219?",
        "a": "The 95/170/32 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 148 kN / C0 118 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7219",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×170×32 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7219-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×170×32 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7219-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×170×32 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7219-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×170×32 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7219-BEGAPH",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×170×32 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7219-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×170×32 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7219",
      "7219-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7219B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7219B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 95,
    "D_mm": 170,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 134,
    "static_load_kN": 107,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 7,
    "limiting_speed_rpm": 3500,
    "max_rpm": 3500,
    "speed_oil_rpm": 4700,
    "weight_g": 2720,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 95 x 170 x 32 mm, NTN 7219B sits in the medium-duty 7200 single-row family of the angular-contact programme. Decoding 7219B: 72 is the single-row dimension series (medium-duty 7200 single-row family), with 19 encodes the 95 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Catalogue mass is about 2720 g, which at this 37.5 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Size selection is usually finished by checking that the C0 of 107 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "Bearings of 95 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 134/107 kN ratings and 7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7219B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7219B?",
        "a": "7219B is a single-row angular contact ball bearing to ISO 15: 95 mm bore, 170 mm outside diameter, 32 mm width (3.74 x 6.693 x 1.26 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 134 kN, C0 107 kN and a 7 kN fatigue load limit Pu; the grease limiting speed is 3,500 r/min and the oil rating 4,700 r/min; mass about 2720 g."
      },
      {
        "q": "How is the 7219B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 19 encodes the 95 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 170 mm OD and 32 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7219B support?",
        "a": "One 7219B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7219B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,500 r/min and the oil rating 4,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7219B?",
        "a": "The 95/170/32 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 134 kN / C0 107 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7219B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7219b",
      "7219B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ219",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ219",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 95,
    "D_mm": 170,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 186,
    "static_load_kN": 335,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 12.4,
    "limiting_speed_rpm": 3000,
    "max_rpm": 3000,
    "speed_oil_rpm": 3900,
    "weight_g": 3350,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, QJ219 appears as a medium-duty QJ200 four-point family bearing of 95 mm bore, 170 mm outside diameter and 32 mm width. Two fields make up the code — QJ2 is the four-point dimension series (medium-duty QJ200 four-point family) and the last two digits 19 give the bore by the standard code table (95 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The radial section height here is 37.5 mm, and the catalogue couples that with C 186 kN / C0 335 kN. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 95 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 3,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 186/335 kN ratings and 12.4 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ219; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ219?",
        "a": "QJ219 is a four-point contact ball bearing to ISO 15: 95 mm bore, 170 mm outside diameter, 32 mm width (3.74 x 6.693 x 1.26 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 186 kN, C0 335 kN and a 12.4 kN fatigue load limit Pu; the grease limiting speed is 3,000 r/min and the oil rating 3,900 r/min; mass about 3350 g."
      },
      {
        "q": "How is the QJ219 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 19 give the bore by the standard code table (95 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 170 mm OD and 32 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ219 support?",
        "a": "QJ219 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ219?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,000 r/min and the oil rating 3,900 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ219?",
        "a": "The 95/170/32 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 186 kN / C0 335 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ219",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj219",
      "QJ219"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7319-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7319",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 95,
    "D_mm": 200,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 202,
    "static_load_kN": 162,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 10.5,
    "limiting_speed_rpm": 3700,
    "max_rpm": 3700,
    "speed_oil_rpm": 5000,
    "weight_g": 5890,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7319 is the 95 mm bore member of NTN's heavy-duty 7300 single-row family, with a 200 mm outside diameter and 45 mm section width. NTN builds the number from 73 is the single-row dimension series (heavy-duty 7300 single-row family), then 19 encodes the 95 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. At roughly 52.5 mm of radial section, the catalogue still quotes 202 kN dynamic capacity for the 95 mm bore. Size selection is usually finished by checking that the C0 of 162 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 95 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The C0 of 162 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Grease rated for deep-groove motor duty is not automatically right at 3,700 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 202/162 kN ratings and 10.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7319; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7319?",
        "a": "7319 is a single-row angular contact ball bearing to ISO 15: 95 mm bore, 200 mm outside diameter, 45 mm width (3.74 x 7.874 x 1.772 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 202 kN, C0 162 kN and a 10.5 kN fatigue load limit Pu; the grease limiting speed is 3,700 r/min and the oil rating 5,000 r/min; mass about 5890 g."
      },
      {
        "q": "How is the 7319 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 19 encodes the 95 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 200 mm OD and 45 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7319 support?",
        "a": "One 7319 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7319?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,700 r/min and the oil rating 5,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7319?",
        "a": "The 95/200/45 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 202 kN / C0 162 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7319",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×200×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7319-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×200×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7319-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×200×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7319-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×200×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7319-BEM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×200×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7319-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 95×200×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7319",
      "7319-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7319B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7319B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 95,
    "D_mm": 200,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 185,
    "static_load_kN": 149,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 9.6,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "speed_oil_rpm": 4200,
    "weight_g": 6000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7319B belongs to the heavy-duty 7300 single-row family: the catalogue boundary dimensions read 95 / 200 / 45 mm (bore / OD / width). Reading the code: 73 is the single-row dimension series (heavy-duty 7300 single-row family), 19 encodes the 95 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 40 deg contact angle is the lever that turns the 149 kN static rating into useful one-direction thrust capacity. Choose the heavy-duty 7300 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Grease quantity matters as much as grade at 3,200 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 95 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7319B without re-checking axial float, heat and housing width — the kinematics differ.",
      "A 7319B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "A 7319B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 185/149 kN ratings and 9.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7319B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7319B?",
        "a": "7319B is a single-row angular contact ball bearing to ISO 15: 95 mm bore, 200 mm outside diameter, 45 mm width (3.74 x 7.874 x 1.772 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 185 kN, C0 149 kN and a 9.6 kN fatigue load limit Pu; the grease limiting speed is 3,200 r/min and the oil rating 4,200 r/min; mass about 6000 g."
      },
      {
        "q": "How is the 7319B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 19 encodes the 95 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 200 mm OD and 45 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7319B support?",
        "a": "One 7319B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7319B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,200 r/min and the oil rating 4,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7319B?",
        "a": "The 95/200/45 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 185 kN / C0 149 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7319B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7319b",
      "7319B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ319",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ319",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 95,
    "D_mm": 200,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 251,
    "static_load_kN": 450,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 16,
    "limiting_speed_rpm": 2700,
    "max_rpm": 2700,
    "speed_oil_rpm": 3500,
    "weight_g": 7410,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The heavy-duty QJ300 four-point family entry QJ319 carries a 95 mm bore in a 200 mm outside diameter, 45 mm wide envelope. Reading the code: QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family), the last two digits 19 give the bore by the standard code table (95 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. With C 251 kN and C0 450 kN, each mm of bore carries about 2.64 kN of dynamic rating. The 95/200/45 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 95 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "The 2,700 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "On a 95 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 251/450 kN ratings and 16 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ319; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ319?",
        "a": "QJ319 is a four-point contact ball bearing to ISO 15: 95 mm bore, 200 mm outside diameter, 45 mm width (3.74 x 7.874 x 1.772 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 251 kN, C0 450 kN and a 16 kN fatigue load limit Pu; the grease limiting speed is 2,700 r/min and the oil rating 3,500 r/min; mass about 7410 g."
      },
      {
        "q": "How is the QJ319 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 19 give the bore by the standard code table (95 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 200 mm OD and 45 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ319 support?",
        "a": "QJ319 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ319?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,700 r/min and the oil rating 3,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ319?",
        "a": "The 95/200/45 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 251 kN / C0 450 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ319",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj319",
      "QJ319"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7920",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7920",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 100,
    "D_mm": 140,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 53,
    "static_load_kN": 52.5,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 3.2,
    "limiting_speed_rpm": 4700,
    "max_rpm": 4700,
    "speed_oil_rpm": 6200,
    "weight_g": 934,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7920 is the 100 mm bore member of NTN's extra-light, high-speed 7900 single-row family, with a 140 mm outside diameter and 20 mm section width. The designation breaks down as 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 20 encodes the 100 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The radial section height here is 20.0 mm, and the catalogue couples that with C 53 kN / C0 52.5 kN. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Grease quantity matters as much as grade at 4,700 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 100 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 52.5 kN really covers the worst static case before substituting it for a 7000.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Grease rated for deep-groove motor duty is not automatically right at 4,700 r/min with preload; check the grease speed factor against the catalogue figure.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 53/52.5 kN ratings and 3.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7920; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7920?",
        "a": "7920 is a single-row angular contact ball bearing to ISO 15: 100 mm bore, 140 mm outside diameter, 20 mm width (3.937 x 5.512 x 0.787 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 53 kN, C0 52.5 kN and a 3.2 kN fatigue load limit Pu; the grease limiting speed is 4,700 r/min and the oil rating 6,200 r/min; mass about 934 g."
      },
      {
        "q": "How is the 7920 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 20 encodes the 100 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 140 mm OD and 20 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7920 support?",
        "a": "One 7920 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7920?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,700 r/min and the oil rating 6,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7920?",
        "a": "The 100/140/20 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 53 kN / C0 52.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7920",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7920"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7020-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7020",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 100,
    "D_mm": 150,
    "B_mm": 24,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 75.5,
    "static_load_kN": 70.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 4.35,
    "limiting_speed_rpm": 4400,
    "max_rpm": 4400,
    "speed_oil_rpm": 5800,
    "weight_g": 1470,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The standard-section 7000 single-row family entry 7020 carries a 100 mm bore in a 150 mm outside diameter, 24 mm wide envelope. Reading the code: 70 is the single-row dimension series (standard-section 7000 single-row family), 20 encodes the 100 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 30 deg contact angle is the lever that turns the 70.5 kN static rating into useful one-direction thrust capacity. Size selection is usually finished by checking that the C0 of 70.5 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 100 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Grease rated for deep-groove motor duty is not automatically right at 4,400 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 4,400 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "A 7020 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 75.5/70.5 kN ratings and 4.35 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7020; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7020?",
        "a": "7020 is a single-row angular contact ball bearing to ISO 15: 100 mm bore, 150 mm outside diameter, 24 mm width (3.937 x 5.906 x 0.945 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 75.5 kN, C0 70.5 kN and a 4.35 kN fatigue load limit Pu; the grease limiting speed is 4,400 r/min and the oil rating 5,800 r/min; mass about 1470 g."
      },
      {
        "q": "How is the 7020 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 20 encodes the 100 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 150 mm OD and 24 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7020 support?",
        "a": "One 7020 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7020?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,400 r/min and the oil rating 5,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7020?",
        "a": "The 100/150/24 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 75.5 kN / C0 70.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7020",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7020",
      "7020-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7220-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7220",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 100,
    "D_mm": 180,
    "B_mm": 34,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 159,
    "static_load_kN": 126,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 8.3,
    "limiting_speed_rpm": 3900,
    "max_rpm": 3900,
    "speed_oil_rpm": 5200,
    "weight_g": 3200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 7200 single-row family entry 7220 carries a 100 mm bore in a 180 mm outside diameter, 34 mm wide envelope. NTN builds the number from 72 is the single-row dimension series (medium-duty 7200 single-row family), then 20 encodes the 100 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Heat-mounting to 80-90 deg C is the clean route onto a 100 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 100 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The C0 of 126 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "On a 100 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 3,900 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 159/126 kN ratings and 8.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7220; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7220?",
        "a": "7220 is a single-row angular contact ball bearing to ISO 15: 100 mm bore, 180 mm outside diameter, 34 mm width (3.937 x 7.087 x 1.339 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 159 kN, C0 126 kN and a 8.3 kN fatigue load limit Pu; the grease limiting speed is 3,900 r/min and the oil rating 5,200 r/min; mass about 3200 g."
      },
      {
        "q": "How is the 7220 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 20 encodes the 100 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 180 mm OD and 34 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7220 support?",
        "a": "One 7220 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7220?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,900 r/min and the oil rating 5,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7220?",
        "a": "The 100/180/34 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 159 kN / C0 126 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7220",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 100×180×34 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7220-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 100×180×34 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7220-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 100×180×34 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7220-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 100×180×34 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7220-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 100×180×34 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7220",
      "7220-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7220B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7220B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 100,
    "D_mm": 180,
    "B_mm": 34,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 144,
    "static_load_kN": 114,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 7.3,
    "limiting_speed_rpm": 3400,
    "max_rpm": 3400,
    "speed_oil_rpm": 4500,
    "weight_g": 3260,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7220B is an NTN single-row angular contact ball bearing: medium-duty 7200 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 100 x 180 x 34 mm. NTN builds the number from 72 is the single-row dimension series (medium-duty 7200 single-row family), then 20 encodes the 100 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Catalogue mass is about 3260 g, which at this 40.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Against a deep-groove bearing of the same 100 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. A 100 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 100 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 144/114 kN ratings and 7.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7220B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7220B?",
        "a": "7220B is a single-row angular contact ball bearing to ISO 15: 100 mm bore, 180 mm outside diameter, 34 mm width (3.937 x 7.087 x 1.339 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 144 kN, C0 114 kN and a 7.3 kN fatigue load limit Pu; the grease limiting speed is 3,400 r/min and the oil rating 4,500 r/min; mass about 3260 g."
      },
      {
        "q": "How is the 7220B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 20 encodes the 100 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 180 mm OD and 34 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7220B support?",
        "a": "One 7220B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7220B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,400 r/min and the oil rating 4,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7220B?",
        "a": "The 100/180/34 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 144 kN / C0 114 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7220B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7220b",
      "7220B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ220",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ220",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 100,
    "D_mm": 180,
    "B_mm": 34,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 200,
    "static_load_kN": 355,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 12.9,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "speed_oil_rpm": 3700,
    "weight_g": 4020,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN QJ220 belongs to the medium-duty QJ200 four-point family: the catalogue boundary dimensions read 100 / 180 / 34 mm (bore / OD / width). The designation breaks down as QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 20 give the bore by the standard code table (100 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The static margin, C0 355 kN versus C 200 kN, is what supports slow oscillating duty and shock without immediate brinelling. For a 100 mm shaft with combined load, the practical shortlist is this series, its neighbouring dimension series, and — where thrust reverses — a back-to-back pair rather than a single row. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 100 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "On a 100 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Do not pair two random QJ220 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 200/355 kN ratings and 12.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ220; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ220?",
        "a": "QJ220 is a four-point contact ball bearing to ISO 15: 100 mm bore, 180 mm outside diameter, 34 mm width (3.937 x 7.087 x 1.339 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 200 kN, C0 355 kN and a 12.9 kN fatigue load limit Pu; the grease limiting speed is 2,800 r/min and the oil rating 3,700 r/min; mass about 4020 g."
      },
      {
        "q": "How is the QJ220 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 20 give the bore by the standard code table (100 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 180 mm OD and 34 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ220 support?",
        "a": "QJ220 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ220?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,800 r/min and the oil rating 3,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ220?",
        "a": "The 100/180/34 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 200 kN / C0 355 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ220",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj220",
      "QJ220"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7320-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7320",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 100,
    "D_mm": 215,
    "B_mm": 47,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 230,
    "static_load_kN": 193,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 12,
    "limiting_speed_rpm": 3500,
    "max_rpm": 3500,
    "speed_oil_rpm": 4700,
    "weight_g": 7180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 100 x 215 x 47 mm, NTN 7320 sits in the heavy-duty 7300 single-row family of the angular-contact programme. Decoding 7320: 73 is the single-row dimension series (heavy-duty 7300 single-row family), with 20 encodes the 100 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The radial section height here is 57.5 mm, and the catalogue couples that with C 230 kN / C0 193 kN. For a 100 mm shaft with combined load, the practical shortlist is this series, its 7200-series lighter section, and — where thrust reverses — a back-to-back pair rather than a single row. A 100 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "Bearings of 100 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7320 without re-checking axial float, heat and housing width — the kinematics differ.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 230/193 kN ratings and 12 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7320; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7320?",
        "a": "7320 is a single-row angular contact ball bearing to ISO 15: 100 mm bore, 215 mm outside diameter, 47 mm width (3.937 x 8.465 x 1.85 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 230 kN, C0 193 kN and a 12 kN fatigue load limit Pu; the grease limiting speed is 3,500 r/min and the oil rating 4,700 r/min; mass about 7180 g."
      },
      {
        "q": "How is the 7320 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 20 encodes the 100 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 215 mm OD and 47 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7320 support?",
        "a": "One 7320 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7320?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,500 r/min and the oil rating 4,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7320?",
        "a": "The 100/215/47 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 230 kN / C0 193 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7320",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 100×215×47 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7320-BECBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7320-BECBP",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7320-BECBY",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      },
      {
        "equiv_sku": "7320-BEM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 100×215×47 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7320-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 100×215×47 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7320",
      "7320-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7320B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7320B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 100,
    "D_mm": 215,
    "B_mm": 47,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 211,
    "static_load_kN": 178,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 11.1,
    "limiting_speed_rpm": 3000,
    "max_rpm": 3000,
    "speed_oil_rpm": 4000,
    "weight_g": 7320,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7320B is the 100 mm bore member of NTN's heavy-duty 7300 single-row family, with a 215 mm outside diameter and 47 mm section width. Two fields make up the code — 73 is the single-row dimension series (heavy-duty 7300 single-row family) and 20 encodes the 100 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). NTN prints 211 kN dynamic and 178 kN static for this size and a 11.1 kN fatigue load limit Pu. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. A 100 mm shaft typically takes a k5/m5 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 100 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Do not pair two random 7320B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7320B without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 211/178 kN ratings and 11.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7320B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7320B?",
        "a": "7320B is a single-row angular contact ball bearing to ISO 15: 100 mm bore, 215 mm outside diameter, 47 mm width (3.937 x 8.465 x 1.85 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 211 kN, C0 178 kN and a 11.1 kN fatigue load limit Pu; the grease limiting speed is 3,000 r/min and the oil rating 4,000 r/min; mass about 7320 g."
      },
      {
        "q": "How is the 7320B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 20 encodes the 100 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 215 mm OD and 47 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7320B support?",
        "a": "One 7320B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7320B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,000 r/min and the oil rating 4,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7320B?",
        "a": "The 100/215/47 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 211 kN / C0 178 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7320B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7320b",
      "7320B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ320",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ320",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 100,
    "D_mm": 215,
    "B_mm": 47,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 300,
    "static_load_kN": 585,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 20,
    "limiting_speed_rpm": 2500,
    "max_rpm": 2500,
    "speed_oil_rpm": 3400,
    "weight_g": 9140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 100 x 215 x 47 mm, NTN QJ320 sits in the heavy-duty QJ300 four-point family of the angular-contact programme. NTN builds the number from QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family), then the last two digits 20 give the bore by the standard code table (100 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. At roughly 57.5 mm of radial section, the catalogue still quotes 300 kN dynamic capacity for the 100 mm bore. Size selection is usually finished by checking that the C0 of 585 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 100 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "On a 100 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 300/585 kN ratings and 20 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ320; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ320?",
        "a": "QJ320 is a four-point contact ball bearing to ISO 15: 100 mm bore, 215 mm outside diameter, 47 mm width (3.937 x 8.465 x 1.85 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 300 kN, C0 585 kN and a 20 kN fatigue load limit Pu; the grease limiting speed is 2,500 r/min and the oil rating 3,400 r/min; mass about 9140 g."
      },
      {
        "q": "How is the QJ320 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 20 give the bore by the standard code table (100 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 215 mm OD and 47 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ320 support?",
        "a": "QJ320 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ320?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,500 r/min and the oil rating 3,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ320?",
        "a": "The 100/215/47 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 300 kN / C0 585 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ320",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj320",
      "QJ320"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7921",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7921",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 105,
    "D_mm": 145,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 54,
    "static_load_kN": 54.5,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 3.25,
    "limiting_speed_rpm": 4400,
    "max_rpm": 4400,
    "speed_oil_rpm": 5900,
    "weight_g": 972,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the extra-light, high-speed 7900 single-row family, 7921 measures 105 mm across the bore, 145 mm over the outer ring and 20 mm across the faces. Reading the code: 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), 21 encodes the 105 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 30 deg contact angle is the lever that turns the 54.5 kN static rating into useful one-direction thrust capacity. The 105/145/20 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 105 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 54.5 kN really covers the worst static case before substituting it for a 7000.",
      "A 7921 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The C0 of 54.5 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "A 7921 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 54/54.5 kN ratings and 3.25 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7921; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7921?",
        "a": "7921 is a single-row angular contact ball bearing to ISO 15: 105 mm bore, 145 mm outside diameter, 20 mm width (4.134 x 5.709 x 0.787 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 54 kN, C0 54.5 kN and a 3.25 kN fatigue load limit Pu; the grease limiting speed is 4,400 r/min and the oil rating 5,900 r/min; mass about 972 g."
      },
      {
        "q": "How is the 7921 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 21 encodes the 105 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 145 mm OD and 20 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7921 support?",
        "a": "One 7921 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7921?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,400 r/min and the oil rating 5,900 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7921?",
        "a": "The 105/145/20 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 54 kN / C0 54.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7921",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7921"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7021-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7021",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 105,
    "D_mm": 160,
    "B_mm": 26,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 88.5,
    "static_load_kN": 81.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 4.95,
    "limiting_speed_rpm": 4100,
    "max_rpm": 4100,
    "speed_oil_rpm": 5500,
    "weight_g": 1860,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7021 belongs to the standard-section 7000 single-row family: the catalogue boundary dimensions read 105 / 160 / 26 mm (bore / OD / width). Decoding 7021: 70 is the single-row dimension series (standard-section 7000 single-row family), with 21 encodes the 105 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. With C 88.5 kN and C0 81.5 kN, each mm of bore carries about 0.84 kN of dynamic rating. The 105/160/26 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Heat-mounting to 80-90 deg C is the clean route onto a 105 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "Bearings of 105 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A 7021 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "On a 105 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 88.5/81.5 kN ratings and 4.95 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7021; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7021?",
        "a": "7021 is a single-row angular contact ball bearing to ISO 15: 105 mm bore, 160 mm outside diameter, 26 mm width (4.134 x 6.299 x 1.024 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 88.5 kN, C0 81.5 kN and a 4.95 kN fatigue load limit Pu; the grease limiting speed is 4,100 r/min and the oil rating 5,500 r/min; mass about 1860 g."
      },
      {
        "q": "How is the 7021 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 21 encodes the 105 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 160 mm OD and 26 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7021 support?",
        "a": "One 7021 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7021?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,100 r/min and the oil rating 5,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7021?",
        "a": "The 105/160/26 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 88.5 kN / C0 81.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7021",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7021",
      "7021-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7221-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7221",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 105,
    "D_mm": 190,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 173,
    "static_load_kN": 142,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 9.1,
    "limiting_speed_rpm": 3700,
    "max_rpm": 3700,
    "speed_oil_rpm": 5000,
    "weight_g": 3790,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 105 x 190 x 36 mm, NTN 7221 sits in the medium-duty 7200 single-row family of the angular-contact programme. Reading the code: 72 is the single-row dimension series (medium-duty 7200 single-row family), 21 encodes the 105 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue mass is about 3790 g, which at this 42.5 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Against a deep-groove bearing of the same 105 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Heat-mounting to 80-90 deg C is the clean route onto a 105 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 105 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The 3,700 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "A 7221 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 173/142 kN ratings and 9.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7221; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7221?",
        "a": "7221 is a single-row angular contact ball bearing to ISO 15: 105 mm bore, 190 mm outside diameter, 36 mm width (4.134 x 7.48 x 1.417 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 173 kN, C0 142 kN and a 9.1 kN fatigue load limit Pu; the grease limiting speed is 3,700 r/min and the oil rating 5,000 r/min; mass about 3790 g."
      },
      {
        "q": "How is the 7221 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 21 encodes the 105 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 190 mm OD and 36 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7221 support?",
        "a": "One 7221 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7221?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,700 r/min and the oil rating 5,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7221?",
        "a": "The 105/190/36 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 173 kN / C0 142 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7221",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 105×190×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7221-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 105×190×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7221-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 105×190×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7221",
      "7221-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7221B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7221B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 105,
    "D_mm": 190,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 157,
    "static_load_kN": 129,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 8.05,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "speed_oil_rpm": 4300,
    "weight_g": 3870,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 7200 single-row family entry 7221B carries a 105 mm bore in a 190 mm outside diameter, 36 mm wide envelope. Reading the code: 72 is the single-row dimension series (medium-duty 7200 single-row family), 21 encodes the 105 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 40 deg contact angle is the lever that turns the 129 kN static rating into useful one-direction thrust capacity. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 105 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7221B without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 3,200 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "A 7221B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 157/129 kN ratings and 8.05 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7221B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7221B?",
        "a": "7221B is a single-row angular contact ball bearing to ISO 15: 105 mm bore, 190 mm outside diameter, 36 mm width (4.134 x 7.48 x 1.417 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 157 kN, C0 129 kN and a 8.05 kN fatigue load limit Pu; the grease limiting speed is 3,200 r/min and the oil rating 4,300 r/min; mass about 3870 g."
      },
      {
        "q": "How is the 7221B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 21 encodes the 105 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 190 mm OD and 36 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7221B support?",
        "a": "One 7221B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7221B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,200 r/min and the oil rating 4,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7221B?",
        "a": "The 105/190/36 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 157 kN / C0 129 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7221B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7221b",
      "7221B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ221",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ221",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 105,
    "D_mm": 190,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 218,
    "static_load_kN": 400,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 14.2,
    "limiting_speed_rpm": 2700,
    "max_rpm": 2700,
    "speed_oil_rpm": 3600,
    "weight_g": 4750,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty QJ200 four-point family entry QJ221 carries a 105 mm bore in a 190 mm outside diameter, 36 mm wide envelope. Reading the code: QJ2 is the four-point dimension series (medium-duty QJ200 four-point family), the last two digits 21 give the bore by the standard code table (105 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The oil rating of 3,600 r/min sits 900 r/min above the 2,700 r/min grease figure — a 1.33x step that says how much headroom oil cooling buys. Against a deep-groove bearing of the same 105 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 105 mm bore give the working limits. ",
    "applications": [
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 105 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single QJ221 without re-checking axial float, heat and housing width — the kinematics differ.",
      "On a 105 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Grease rated for deep-groove motor duty is not automatically right at 2,700 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 218/400 kN ratings and 14.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ221; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ221?",
        "a": "QJ221 is a four-point contact ball bearing to ISO 15: 105 mm bore, 190 mm outside diameter, 36 mm width (4.134 x 7.48 x 1.417 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 218 kN, C0 400 kN and a 14.2 kN fatigue load limit Pu; the grease limiting speed is 2,700 r/min and the oil rating 3,600 r/min; mass about 4750 g."
      },
      {
        "q": "How is the QJ221 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 21 give the bore by the standard code table (105 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 190 mm OD and 36 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ221 support?",
        "a": "QJ221 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ221?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,700 r/min and the oil rating 3,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ221?",
        "a": "The 105/190/36 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 218 kN / C0 400 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ221",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj221",
      "QJ221"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7321-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7321",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 105,
    "D_mm": 225,
    "B_mm": 49,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 244,
    "static_load_kN": 210,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 12.8,
    "limiting_speed_rpm": 3400,
    "max_rpm": 3400,
    "speed_oil_rpm": 4500,
    "weight_g": 8200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The heavy-duty 7300 single-row family entry 7321 carries a 105 mm bore in a 225 mm outside diameter, 49 mm wide envelope. The designation breaks down as 73 is the single-row dimension series (heavy-duty 7300 single-row family); 21 encodes the 105 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. On speed, the grease limiting speed is 3,400 r/min and the oil rating 4,500 r/min. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 105 mm bore give the working limits. ",
    "applications": [
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 105 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The C0 of 210 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The C0 of 210 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 244/210 kN ratings and 12.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7321; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7321?",
        "a": "7321 is a single-row angular contact ball bearing to ISO 15: 105 mm bore, 225 mm outside diameter, 49 mm width (4.134 x 8.858 x 1.929 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 244 kN, C0 210 kN and a 12.8 kN fatigue load limit Pu; the grease limiting speed is 3,400 r/min and the oil rating 4,500 r/min; mass about 8200 g."
      },
      {
        "q": "How is the 7321 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 21 encodes the 105 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 225 mm OD and 49 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7321 support?",
        "a": "One 7321 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7321?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,400 r/min and the oil rating 4,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7321?",
        "a": "The 105/225/49 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 244 kN / C0 210 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7321",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 105×225×49 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7321-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 105×225×49 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7321-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 105×225×49 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7321-DECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 105×225×49 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7321",
      "7321-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7321B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7321B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 105,
    "D_mm": 225,
    "B_mm": 49,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 224,
    "static_load_kN": 194,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 11.8,
    "limiting_speed_rpm": 2900,
    "max_rpm": 2900,
    "speed_oil_rpm": 3800,
    "weight_g": 8360,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7321B appears as a heavy-duty 7300 single-row family bearing of 105 mm bore, 225 mm outside diameter and 49 mm width. NTN builds the number from 73 is the single-row dimension series (heavy-duty 7300 single-row family), then 21 encodes the 105 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Catalogue mass is about 8360 g, which at this 60.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "Bearings of 105 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Grease rated for deep-groove motor duty is not automatically right at 2,900 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 224/194 kN ratings and 11.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7321B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7321B?",
        "a": "7321B is a single-row angular contact ball bearing to ISO 15: 105 mm bore, 225 mm outside diameter, 49 mm width (4.134 x 8.858 x 1.929 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 224 kN, C0 194 kN and a 11.8 kN fatigue load limit Pu; the grease limiting speed is 2,900 r/min and the oil rating 3,800 r/min; mass about 8360 g."
      },
      {
        "q": "How is the 7321B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 21 encodes the 105 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 225 mm OD and 49 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7321B support?",
        "a": "One 7321B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7321B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,900 r/min and the oil rating 3,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7321B?",
        "a": "The 105/225/49 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 224 kN / C0 194 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7321B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7321b",
      "7321B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ321",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ321",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 105,
    "D_mm": 225,
    "B_mm": 49,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 305,
    "static_load_kN": 585,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 19.6,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "speed_oil_rpm": 3200,
    "weight_g": 10400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "QJ321 is the 105 mm bore member of NTN's heavy-duty QJ300 four-point family, with a 225 mm outside diameter and 49 mm section width. The designation breaks down as QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 21 give the bore by the standard code table (105 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. NTN prints 305 kN dynamic and 585 kN static for this size and a 19.6 kN fatigue load limit Pu. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 105 mm bore give the working limits. ",
    "applications": [
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 105 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single QJ321 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 305/585 kN ratings and 19.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ321; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ321?",
        "a": "QJ321 is a four-point contact ball bearing to ISO 15: 105 mm bore, 225 mm outside diameter, 49 mm width (4.134 x 8.858 x 1.929 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 305 kN, C0 585 kN and a 19.6 kN fatigue load limit Pu; the grease limiting speed is 2,400 r/min and the oil rating 3,200 r/min; mass about 10400 g."
      },
      {
        "q": "How is the QJ321 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 21 give the bore by the standard code table (105 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 225 mm OD and 49 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ321 support?",
        "a": "QJ321 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ321?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,400 r/min and the oil rating 3,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ321?",
        "a": "The 105/225/49 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 305 kN / C0 585 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ321",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj321",
      "QJ321"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7922",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7922",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 110,
    "D_mm": 150,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 54.5,
    "static_load_kN": 56,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 3.25,
    "limiting_speed_rpm": 4200,
    "max_rpm": 4200,
    "speed_oil_rpm": 5700,
    "weight_g": 1010,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7922 is an NTN single-row angular contact ball bearing: extra-light, high-speed 7900 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 110 x 150 x 20 mm. Two fields make up the code — 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family) and 22 encodes the 110 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. On speed, the grease limiting speed is 4,200 r/min and the oil rating 5,700 r/min. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. A 110 mm shaft typically takes a m6/n6 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts",
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 110 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 56 kN really covers the worst static case before substituting it for a 7000.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The C0 of 56 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 54.5/56 kN ratings and 3.25 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7922; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7922?",
        "a": "7922 is a single-row angular contact ball bearing to ISO 15: 110 mm bore, 150 mm outside diameter, 20 mm width (4.331 x 5.906 x 0.787 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 54.5 kN, C0 56 kN and a 3.25 kN fatigue load limit Pu; the grease limiting speed is 4,200 r/min and the oil rating 5,700 r/min; mass about 1010 g."
      },
      {
        "q": "How is the 7922 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 22 encodes the 110 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 150 mm OD and 20 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7922 support?",
        "a": "One 7922 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7922?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 4,200 r/min and the oil rating 5,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7922?",
        "a": "The 110/150/20 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 54.5 kN / C0 56 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7922",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7922"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7022-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7022",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 110,
    "D_mm": 170,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 102,
    "static_load_kN": 93,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 5.5,
    "limiting_speed_rpm": 3900,
    "max_rpm": 3900,
    "speed_oil_rpm": 5300,
    "weight_g": 2300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The standard-section 7000 single-row family entry 7022 carries a 110 mm bore in a 170 mm outside diameter, 28 mm wide envelope. The designation breaks down as 70 is the single-row dimension series (standard-section 7000 single-row family); 22 encodes the 110 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The static margin, C0 93 kN versus C 102 kN, is what supports slow oscillating duty and shock without immediate brinelling. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Heat-mounting to 80-90 deg C is the clean route onto a 110 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions",
      "marine auxiliary and winch gearbox shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "Bearings of 110 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7022 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Grease rated for deep-groove motor duty is not automatically right at 3,900 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Do not pair two random 7022 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 102/93 kN ratings and 5.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7022; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7022?",
        "a": "7022 is a single-row angular contact ball bearing to ISO 15: 110 mm bore, 170 mm outside diameter, 28 mm width (4.331 x 6.693 x 1.102 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 102 kN, C0 93 kN and a 5.5 kN fatigue load limit Pu; the grease limiting speed is 3,900 r/min and the oil rating 5,300 r/min; mass about 2300 g."
      },
      {
        "q": "How is the 7022 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 22 encodes the 110 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 170 mm OD and 28 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7022 support?",
        "a": "One 7022 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7022?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,900 r/min and the oil rating 5,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7022?",
        "a": "The 110/170/28 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 102 kN / C0 93 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7022",
        "equiv_brand": "GENERIC-ISO",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7022",
      "7022-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7222-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7222",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 110,
    "D_mm": 200,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 188,
    "static_load_kN": 158,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 9.95,
    "limiting_speed_rpm": 3500,
    "max_rpm": 3500,
    "speed_oil_rpm": 4700,
    "weight_g": 4450,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 7200 single-row family entry 7222 carries a 110 mm bore in a 200 mm outside diameter, 38 mm wide envelope. Decoding 7222: 72 is the single-row dimension series (medium-duty 7200 single-row family), with 22 encodes the 110 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The oil rating of 4,700 r/min sits 1,200 r/min above the 3,500 r/min grease figure — a 1.34x step that says how much headroom oil cooling buys. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 110 mm bore give the working limits. ",
    "applications": [
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "Bearings of 110 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Grease rated for deep-groove motor duty is not automatically right at 3,500 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Grease rated for deep-groove motor duty is not automatically right at 3,500 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 188/158 kN ratings and 9.95 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7222; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7222?",
        "a": "7222 is a single-row angular contact ball bearing to ISO 15: 110 mm bore, 200 mm outside diameter, 38 mm width (4.331 x 7.874 x 1.496 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 188 kN, C0 158 kN and a 9.95 kN fatigue load limit Pu; the grease limiting speed is 3,500 r/min and the oil rating 4,700 r/min; mass about 4450 g."
      },
      {
        "q": "How is the 7222 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 22 encodes the 110 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 200 mm OD and 38 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7222 support?",
        "a": "One 7222 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7222?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,500 r/min and the oil rating 4,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7222?",
        "a": "The 110/200/38 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 188 kN / C0 158 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7222",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×200×38 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7222-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×200×38 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7222-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×200×38 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7222-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×200×38 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7222-BEP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×200×38 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7222",
      "7222-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7222B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7222B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 110,
    "D_mm": 200,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 170,
    "static_load_kN": 144,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 8.8,
    "limiting_speed_rpm": 3000,
    "max_rpm": 3000,
    "speed_oil_rpm": 4000,
    "weight_g": 4540,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 7200 single-row family, 7222B measures 110 mm across the bore, 200 mm over the outer ring and 38 mm across the faces. Decoding 7222B: 72 is the single-row dimension series (medium-duty 7200 single-row family), with 22 encodes the 110 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). With C 170 kN and C0 144 kN, each mm of bore carries about 1.55 kN of dynamic rating. For a 110 mm shaft with combined load, the practical shortlist is this series, its 7300-series heavier section, and — where thrust reverses — a back-to-back pair rather than a single row. Grease quantity matters as much as grade at 3,000 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "Bearings of 110 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "A 7222B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "On a 110 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 170/144 kN ratings and 8.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7222B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7222B?",
        "a": "7222B is a single-row angular contact ball bearing to ISO 15: 110 mm bore, 200 mm outside diameter, 38 mm width (4.331 x 7.874 x 1.496 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 170 kN, C0 144 kN and a 8.8 kN fatigue load limit Pu; the grease limiting speed is 3,000 r/min and the oil rating 4,000 r/min; mass about 4540 g."
      },
      {
        "q": "How is the 7222B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 22 encodes the 110 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 200 mm OD and 38 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7222B support?",
        "a": "One 7222B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7222B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,000 r/min and the oil rating 4,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7222B?",
        "a": "The 110/200/38 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 170 kN / C0 144 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7222B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7222b",
      "7222B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ222",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ222",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 110,
    "D_mm": 200,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 236,
    "static_load_kN": 450,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 15.5,
    "limiting_speed_rpm": 2500,
    "max_rpm": 2500,
    "speed_oil_rpm": 3400,
    "weight_g": 5620,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 110 x 200 x 38 mm, NTN QJ222 sits in the medium-duty QJ200 four-point family of the angular-contact programme. Two fields make up the code — QJ2 is the four-point dimension series (medium-duty QJ200 four-point family) and the last two digits 22 give the bore by the standard code table (110 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. Catalogue dynamic rating C is 236 kN against C0 450 kN — a C0/C ratio of 1.91 that is typical of an angular-contact contact ellipse. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Heat-mounting to 80-90 deg C is the clean route onto a 110 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 110 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "The C0 of 450 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 236/450 kN ratings and 15.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ222; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ222?",
        "a": "QJ222 is a four-point contact ball bearing to ISO 15: 110 mm bore, 200 mm outside diameter, 38 mm width (4.331 x 7.874 x 1.496 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 236 kN, C0 450 kN and a 15.5 kN fatigue load limit Pu; the grease limiting speed is 2,500 r/min and the oil rating 3,400 r/min; mass about 5620 g."
      },
      {
        "q": "How is the QJ222 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 22 give the bore by the standard code table (110 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 200 mm OD and 38 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ222 support?",
        "a": "QJ222 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ222?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,500 r/min and the oil rating 3,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ222?",
        "a": "The 110/200/38 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 236 kN / C0 450 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ222",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj222",
      "QJ222"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7322-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7322",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 110,
    "D_mm": 240,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 273,
    "static_load_kN": 246,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 14.5,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "speed_oil_rpm": 4300,
    "weight_g": 9600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 110 x 240 x 50 mm, NTN 7322 sits in the heavy-duty 7300 single-row family of the angular-contact programme. Two fields make up the code — 73 is the single-row dimension series (heavy-duty 7300 single-row family) and 22 encodes the 110 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. With C 273 kN and C0 246 kN, each mm of bore carries about 2.48 kN of dynamic rating. Against a deep-groove bearing of the same 110 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 110 mm bore give the working limits. ",
    "applications": [
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts",
      "mining conveyor head-shaft positions"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 110 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The 3,200 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Do not pair two random 7322 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "On a 110 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 273/246 kN ratings and 14.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7322; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7322?",
        "a": "7322 is a single-row angular contact ball bearing to ISO 15: 110 mm bore, 240 mm outside diameter, 50 mm width (4.331 x 9.449 x 1.969 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 273 kN, C0 246 kN and a 14.5 kN fatigue load limit Pu; the grease limiting speed is 3,200 r/min and the oil rating 4,300 r/min; mass about 9600 g."
      },
      {
        "q": "How is the 7322 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 22 encodes the 110 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 240 mm OD and 50 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7322 support?",
        "a": "One 7322 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7322?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,200 r/min and the oil rating 4,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7322?",
        "a": "The 110/240/50 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 273 kN / C0 246 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7322",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×240×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7322-BECBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×240×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7322-BECBP",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×240×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7322-BECBY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×240×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7322-BEM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×240×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7322-BEY",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×240×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7322",
      "7322-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7322B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7322B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 110,
    "D_mm": 240,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 250,
    "static_load_kN": 226,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 13.3,
    "limiting_speed_rpm": 2700,
    "max_rpm": 2700,
    "speed_oil_rpm": 3700,
    "weight_g": 9800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 110 x 240 x 50 mm, NTN 7322B sits in the heavy-duty 7300 single-row family of the angular-contact programme. Reading the code: 73 is the single-row dimension series (heavy-duty 7300 single-row family), 22 encodes the 110 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 40 deg contact angle is the lever that turns the 226 kN static rating into useful one-direction thrust capacity. The 110/240/50 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Grease quantity matters as much as grade at 2,700 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives",
      "extruder and mixer gearbox output shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 110 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "On a 110 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "A 7322B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 250/226 kN ratings and 13.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7322B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7322B?",
        "a": "7322B is a single-row angular contact ball bearing to ISO 15: 110 mm bore, 240 mm outside diameter, 50 mm width (4.331 x 9.449 x 1.969 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 250 kN, C0 226 kN and a 13.3 kN fatigue load limit Pu; the grease limiting speed is 2,700 r/min and the oil rating 3,700 r/min; mass about 9800 g."
      },
      {
        "q": "How is the 7322B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 22 encodes the 110 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 240 mm OD and 50 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7322B support?",
        "a": "One 7322B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7322B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,700 r/min and the oil rating 3,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7322B?",
        "a": "The 110/240/50 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 250 kN / C0 226 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7322B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7322b",
      "7322B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ322",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ322",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 110,
    "D_mm": 240,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 340,
    "static_load_kN": 680,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 22.1,
    "limiting_speed_rpm": 2300,
    "max_rpm": 2300,
    "speed_oil_rpm": 3100,
    "weight_g": 12000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty QJ300 four-point family, QJ322 measures 110 mm across the bore, 240 mm over the outer ring and 50 mm across the faces. Reading the code: QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family), the last two digits 22 give the bore by the standard code table (110 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. For a 110 mm shaft with combined load, the practical shortlist is this series, its neighbouring dimension series, and — where thrust reverses — a back-to-back pair rather than a single row. Heat-mounting to 80-90 deg C is the clean route onto a 110 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "rolling-mill and metalworking drive shafts",
      "large pump, fan and compressor rotor shafts",
      "crane and hoist gearbox shafts",
      "paper-machine roll and calendar drives"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "Bearings of 110 mm bore arrive heavy enough that handling damage (dents from slings, tilting on the shaft) is a real failure precursor — use proper lifting and heating kit.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Grease rated for deep-groove motor duty is not automatically right at 2,300 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single QJ322 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 2,300 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 340/680 kN ratings and 22.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ322; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ322?",
        "a": "QJ322 is a four-point contact ball bearing to ISO 15: 110 mm bore, 240 mm outside diameter, 50 mm width (4.331 x 9.449 x 1.969 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 340 kN, C0 680 kN and a 22.1 kN fatigue load limit Pu; the grease limiting speed is 2,300 r/min and the oil rating 3,100 r/min; mass about 12000 g."
      },
      {
        "q": "How is the QJ322 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 22 give the bore by the standard code table (110 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 240 mm OD and 50 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ322 support?",
        "a": "QJ322 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ322?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,300 r/min and the oil rating 3,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ322?",
        "a": "The 110/240/50 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 340 kN / C0 680 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ322",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj322",
      "QJ322"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7924",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7924",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 120,
    "D_mm": 165,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 67.5,
    "static_load_kN": 69.5,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 3.9,
    "limiting_speed_rpm": 3900,
    "max_rpm": 3900,
    "speed_oil_rpm": 5200,
    "weight_g": 1660,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7924 belongs to the extra-light, high-speed 7900 single-row family: the catalogue boundary dimensions read 120 / 165 / 22 mm (bore / OD / width). NTN builds the number from 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), then 24 encodes the 120 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The static margin, C0 69.5 kN versus C 67.5 kN, is what supports slow oscillating duty and shock without immediate brinelling. Choose the extra-light, high-speed 7900 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 120 mm bore give the working limits. ",
    "applications": [
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 120 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 69.5 kN really covers the worst static case before substituting it for a 7000.",
      "Grease rated for deep-groove motor duty is not automatically right at 3,900 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Do not pair two random 7924 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Do not pair two random 7924 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 67.5/69.5 kN ratings and 3.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7924; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7924?",
        "a": "7924 is a single-row angular contact ball bearing to ISO 15: 120 mm bore, 165 mm outside diameter, 22 mm width (4.724 x 6.496 x 0.866 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 67.5 kN, C0 69.5 kN and a 3.9 kN fatigue load limit Pu; the grease limiting speed is 3,900 r/min and the oil rating 5,200 r/min; mass about 1660 g."
      },
      {
        "q": "How is the 7924 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 24 encodes the 120 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 165 mm OD and 22 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7924 support?",
        "a": "One 7924 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7924?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,900 r/min and the oil rating 5,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7924?",
        "a": "The 120/165/22 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 67.5 kN / C0 69.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7924",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=131",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7924"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7024",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7024",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 120,
    "D_mm": 180,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 104,
    "static_load_kN": 98.5,
    "cage_type": "steel_stamped_J",
    "fatigue_load_limit_kN": 5.55,
    "limiting_speed_rpm": 3600,
    "max_rpm": 3600,
    "speed_oil_rpm": 4800,
    "weight_g": 2470,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The standard-section 7000 single-row family entry 7024 carries a 120 mm bore in a 180 mm outside diameter, 28 mm wide envelope. Two fields make up the code — 70 is the single-row dimension series (standard-section 7000 single-row family) and 24 encodes the 120 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue dynamic rating C is 104 kN against C0 98.5 kN — a C0/C ratio of 0.95 that is typical of an angular-contact contact ellipse. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 120 mm bore give the working limits. ",
    "applications": [
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 120 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "On a 120 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 104/98.5 kN ratings and 5.55 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7024; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7024?",
        "a": "7024 is a single-row angular contact ball bearing to ISO 15: 120 mm bore, 180 mm outside diameter, 28 mm width (4.724 x 7.087 x 1.102 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 104 kN, C0 98.5 kN and a 5.55 kN fatigue load limit Pu; the grease limiting speed is 3,600 r/min and the oil rating 4,800 r/min; mass about 2470 g."
      },
      {
        "q": "How is the 7024 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 24 encodes the 120 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 180 mm OD and 28 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7024 support?",
        "a": "One 7024 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7024?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,600 r/min and the oil rating 4,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7024?",
        "a": "The 120/180/28 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 104 kN / C0 98.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7024-BGM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×180×28 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7024"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7224",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7224",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 120,
    "D_mm": 215,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 202,
    "static_load_kN": 177,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 10.7,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "speed_oil_rpm": 4300,
    "weight_g": 6260,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7224 is an NTN single-row angular contact ball bearing: medium-duty 7200 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 120 x 215 x 40 mm. The designation breaks down as 72 is the single-row dimension series (medium-duty 7200 single-row family); 24 encodes the 120 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The oil rating of 4,300 r/min sits 1,100 r/min above the 3,200 r/min grease figure — a 1.34x step that says how much headroom oil cooling buys. The 120/215/40 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 120 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The 3,200 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "A 7224 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Grease rated for deep-groove motor duty is not automatically right at 3,200 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 202/177 kN ratings and 10.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7224; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7224?",
        "a": "7224 is a single-row angular contact ball bearing to ISO 15: 120 mm bore, 215 mm outside diameter, 40 mm width (4.724 x 8.465 x 1.575 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 202 kN, C0 177 kN and a 10.7 kN fatigue load limit Pu; the grease limiting speed is 3,200 r/min and the oil rating 4,300 r/min; mass about 6260 g."
      },
      {
        "q": "How is the 7224 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 24 encodes the 120 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 215 mm OD and 40 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7224 support?",
        "a": "One 7224 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7224?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,200 r/min and the oil rating 4,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7224?",
        "a": "The 120/215/40 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 202 kN / C0 177 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7224-BCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×215×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7224-BM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×215×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7224"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7224B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7224B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 120,
    "D_mm": 215,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 183,
    "static_load_kN": 162,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 9.4,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "speed_oil_rpm": 3700,
    "weight_g": 6260,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7224B is the 120 mm bore member of NTN's medium-duty 7200 single-row family, with a 215 mm outside diameter and 40 mm section width. Two fields make up the code — 72 is the single-row dimension series (medium-duty 7200 single-row family) and 24 encodes the 120 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). At roughly 47.5 mm of radial section, the catalogue still quotes 183 kN dynamic capacity for the 120 mm bore. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Heat-mounting to 80-90 deg C is the clean route onto a 120 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 120 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "The C0 of 162 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 183/162 kN ratings and 9.4 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7224B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7224B?",
        "a": "7224B is a single-row angular contact ball bearing to ISO 15: 120 mm bore, 215 mm outside diameter, 40 mm width (4.724 x 8.465 x 1.575 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 183 kN, C0 162 kN and a 9.4 kN fatigue load limit Pu; the grease limiting speed is 2,800 r/min and the oil rating 3,700 r/min; mass about 6260 g."
      },
      {
        "q": "How is the 7224B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 24 encodes the 120 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 215 mm OD and 40 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7224B support?",
        "a": "One 7224B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7224B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,800 r/min and the oil rating 3,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7224B?",
        "a": "The 120/215/40 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 183 kN / C0 162 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7224B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7224b",
      "7224B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ224",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ224",
    "series": "QJ200-series",
    "type": "angular_contact",
    "d_mm": 120,
    "D_mm": 215,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 266,
    "static_load_kN": 540,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 17.7,
    "limiting_speed_rpm": 2300,
    "max_rpm": 2300,
    "speed_oil_rpm": 3100,
    "weight_g": 6750,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty QJ200 four-point family, QJ224 measures 120 mm across the bore, 215 mm over the outer ring and 40 mm across the faces. NTN builds the number from QJ2 is the four-point dimension series (medium-duty QJ200 four-point family), then the last two digits 24 give the bore by the standard code table (120 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. NTN prints 266 kN dynamic and 540 kN static for this size and a 17.7 kN fatigue load limit Pu. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Grease quantity matters as much as grade at 2,300 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 120 mm bore bearing forgives nothing in a poorly machined housing.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "A QJ224 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Grease rated for deep-groove motor duty is not automatically right at 2,300 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single QJ224 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 266/540 kN ratings and 17.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ224; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ224?",
        "a": "QJ224 is a four-point contact ball bearing to ISO 15: 120 mm bore, 215 mm outside diameter, 40 mm width (4.724 x 8.465 x 1.575 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 266 kN, C0 540 kN and a 17.7 kN fatigue load limit Pu; the grease limiting speed is 2,300 r/min and the oil rating 3,100 r/min; mass about 6750 g."
      },
      {
        "q": "How is the QJ224 designation structured?",
        "a": "QJ2 is the four-point dimension series (medium-duty QJ200 four-point family); the last two digits 24 give the bore by the standard code table (120 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 215 mm OD and 40 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ224 support?",
        "a": "QJ224 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ224?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,300 r/min and the oil rating 3,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ224?",
        "a": "The 120/215/40 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 266 kN / C0 540 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ224",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj224",
      "QJ224"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7324",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7324",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 120,
    "D_mm": 260,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 273,
    "static_load_kN": 252,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 14.3,
    "limiting_speed_rpm": 2900,
    "max_rpm": 2900,
    "speed_oil_rpm": 3900,
    "weight_g": 14700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7324 belongs to the heavy-duty 7300 single-row family: the catalogue boundary dimensions read 120 / 260 / 55 mm (bore / OD / width). NTN builds the number from 73 is the single-row dimension series (heavy-duty 7300 single-row family), then 24 encodes the 120 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. NTN prints 273 kN dynamic and 252 kN static for this size and a 14.3 kN fatigue load limit Pu. Against a deep-groove bearing of the same 120 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 120 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A 7324 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 2,900 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7324 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 273/252 kN ratings and 14.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7324; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7324?",
        "a": "7324 is a single-row angular contact ball bearing to ISO 15: 120 mm bore, 260 mm outside diameter, 55 mm width (4.724 x 10.236 x 2.165 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 273 kN, C0 252 kN and a 14.3 kN fatigue load limit Pu; the grease limiting speed is 2,900 r/min and the oil rating 3,900 r/min; mass about 14700 g."
      },
      {
        "q": "How is the 7324 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 24 encodes the 120 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 260 mm OD and 55 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7324 support?",
        "a": "One 7324 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7324?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,900 r/min and the oil rating 3,900 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7324?",
        "a": "The 120/260/55 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 273 kN / C0 252 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7324-BCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×260×55 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7324"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7324B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7324B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 120,
    "D_mm": 260,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 249,
    "static_load_kN": 231,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 13.1,
    "limiting_speed_rpm": 2500,
    "max_rpm": 2500,
    "speed_oil_rpm": 3300,
    "weight_g": 14700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The heavy-duty 7300 single-row family entry 7324B carries a 120 mm bore in a 260 mm outside diameter, 55 mm wide envelope. The designation breaks down as 73 is the single-row dimension series (heavy-duty 7300 single-row family); 24 encodes the 120 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The oil rating of 3,300 r/min sits 800 r/min above the 2,500 r/min grease figure — a 1.32x step that says how much headroom oil cooling buys. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Heat-mounting to 80-90 deg C is the clean route onto a 120 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 120 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Grease rated for deep-groove motor duty is not automatically right at 2,500 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Grease rated for deep-groove motor duty is not automatically right at 2,500 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 249/231 kN ratings and 13.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7324B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7324B?",
        "a": "7324B is a single-row angular contact ball bearing to ISO 15: 120 mm bore, 260 mm outside diameter, 55 mm width (4.724 x 10.236 x 2.165 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 249 kN, C0 231 kN and a 13.1 kN fatigue load limit Pu; the grease limiting speed is 2,500 r/min and the oil rating 3,300 r/min; mass about 14700 g."
      },
      {
        "q": "How is the 7324B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 24 encodes the 120 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 260 mm OD and 55 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7324B support?",
        "a": "One 7324B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7324B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,500 r/min and the oil rating 3,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7324B?",
        "a": "The 120/260/55 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 249 kN / C0 231 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7324B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7324b",
      "7324B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "QJ324",
    "brand": "NTN",
    "manufacturer_designation": "NTN QJ324",
    "series": "QJ300-series",
    "type": "angular_contact",
    "d_mm": 120,
    "D_mm": 260,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 360,
    "static_load_kN": 765,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 23.8,
    "limiting_speed_rpm": 2100,
    "max_rpm": 2100,
    "speed_oil_rpm": 2800,
    "weight_g": 15900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, QJ324 appears as a heavy-duty QJ300 four-point family bearing of 120 mm bore, 260 mm outside diameter and 55 mm width. Decoding QJ324: QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family), with the last two digits 24 give the bore by the standard code table (120 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The radial section height here is 70.0 mm, and the catalogue couples that with C 360 kN / C0 765 kN. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Grease quantity matters as much as grade at 2,100 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 120 mm bore bearing forgives nothing in a poorly machined housing.",
      "The QJ split inner ring must be clamped by the shaft nut/shoulder on both halves — assembling it against a single small shoulder leaves one half-ring free to walk.",
      "Do not pair two random QJ324 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The C0 of 765 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 360/765 kN ratings and 23.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for QJ324; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN QJ324?",
        "a": "QJ324 is a four-point contact ball bearing to ISO 15: 120 mm bore, 260 mm outside diameter, 55 mm width (4.724 x 10.236 x 2.165 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 360 kN, C0 765 kN and a 23.8 kN fatigue load limit Pu; the grease limiting speed is 2,100 r/min and the oil rating 2,800 r/min; mass about 15900 g."
      },
      {
        "q": "How is the QJ324 designation structured?",
        "a": "QJ3 is the four-point dimension series (heavy-duty QJ300 four-point family); the last two digits 24 give the bore by the standard code table (120 mm); there is no suffix — the split inner ring and 35 deg contact angle are inherent to the QJ design. The 260 mm OD and 55 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does QJ324 support?",
        "a": "QJ324 is a four-point contact bearing: the split inner ring lets each ball touch the raceways at two points, so one bearing locates the shaft in both axial directions at its 35 deg contact angle. It is normally mounted with slight radial clearance against the housing as the axial-locating member."
      },
      {
        "q": "What lubrication speeds does NTN print for QJ324?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,100 r/min and the oil rating 2,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for QJ324?",
        "a": "The 120/260/55 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 360 kN / C0 765 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "QJ324",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=134",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "qj324",
      "QJ324"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7926",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7926",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 130,
    "D_mm": 180,
    "B_mm": 24,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 83,
    "static_load_kN": 87.5,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 4.65,
    "limiting_speed_rpm": 3600,
    "max_rpm": 3600,
    "speed_oil_rpm": 4700,
    "weight_g": 1820,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 130 x 180 x 24 mm, NTN 7926 sits in the extra-light, high-speed 7900 single-row family of the angular-contact programme. Reading the code: 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), 26 encodes the 130 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue dynamic rating C is 83 kN against C0 87.5 kN — a C0/C ratio of 1.05 that is typical of an angular-contact contact ellipse. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 130 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 87.5 kN really covers the worst static case before substituting it for a 7000.",
      "Do not pair two random 7926 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 3,600 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 83/87.5 kN ratings and 4.65 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7926; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7926?",
        "a": "7926 is a single-row angular contact ball bearing to ISO 15: 130 mm bore, 180 mm outside diameter, 24 mm width (5.118 x 7.087 x 0.945 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 83 kN, C0 87.5 kN and a 4.65 kN fatigue load limit Pu; the grease limiting speed is 3,600 r/min and the oil rating 4,700 r/min; mass about 1820 g."
      },
      {
        "q": "How is the 7926 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 26 encodes the 130 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 180 mm OD and 24 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7926 support?",
        "a": "One 7926 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7926?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,600 r/min and the oil rating 4,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7926?",
        "a": "The 130/180/24 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 83 kN / C0 87.5 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7926",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7926"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7026",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7026",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 130,
    "D_mm": 200,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 130,
    "static_load_kN": 125,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 6.75,
    "limiting_speed_rpm": 3300,
    "max_rpm": 3300,
    "speed_oil_rpm": 4400,
    "weight_g": 3730,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7026 is the 130 mm bore member of NTN's standard-section 7000 single-row family, with a 200 mm outside diameter and 33 mm section width. NTN builds the number from 70 is the single-row dimension series (standard-section 7000 single-row family), then 26 encodes the 130 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. NTN prints 130 kN dynamic and 125 kN static for this size and a 6.75 kN fatigue load limit Pu. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 130 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The C0 of 125 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Do not pair two random 7026 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7026 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 130/125 kN ratings and 6.75 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7026; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7026?",
        "a": "7026 is a single-row angular contact ball bearing to ISO 15: 130 mm bore, 200 mm outside diameter, 33 mm width (5.118 x 7.874 x 1.299 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 130 kN, C0 125 kN and a 6.75 kN fatigue load limit Pu; the grease limiting speed is 3,300 r/min and the oil rating 4,400 r/min; mass about 3730 g."
      },
      {
        "q": "How is the 7026 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 26 encodes the 130 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 200 mm OD and 33 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7026 support?",
        "a": "One 7026 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7026?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,300 r/min and the oil rating 4,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7026?",
        "a": "The 130/200/33 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 130 kN / C0 125 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7026",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7026"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7226",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7226",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 130,
    "D_mm": 230,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 217,
    "static_load_kN": 198,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 11.5,
    "limiting_speed_rpm": 3000,
    "max_rpm": 3000,
    "speed_oil_rpm": 4000,
    "weight_g": 7150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7226 belongs to the medium-duty 7200 single-row family: the catalogue boundary dimensions read 130 / 230 / 40 mm (bore / OD / width). Two fields make up the code — 72 is the single-row dimension series (medium-duty 7200 single-row family) and 26 encodes the 130 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. At roughly 50.0 mm of radial section, the catalogue still quotes 217 kN dynamic capacity for the 130 mm bore. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 130 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7226 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 217/198 kN ratings and 11.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7226; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7226?",
        "a": "7226 is a single-row angular contact ball bearing to ISO 15: 130 mm bore, 230 mm outside diameter, 40 mm width (5.118 x 9.055 x 1.575 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 217 kN, C0 198 kN and a 11.5 kN fatigue load limit Pu; the grease limiting speed is 3,000 r/min and the oil rating 4,000 r/min; mass about 7150 g."
      },
      {
        "q": "How is the 7226 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 26 encodes the 130 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 230 mm OD and 40 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7226 support?",
        "a": "One 7226 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7226?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,000 r/min and the oil rating 4,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7226?",
        "a": "The 130/230/40 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 217 kN / C0 198 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7226-BCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×230×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7226-BM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×230×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7226"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7226B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7226B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 130,
    "D_mm": 230,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 196,
    "static_load_kN": 180,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 10,
    "limiting_speed_rpm": 2500,
    "max_rpm": 2500,
    "speed_oil_rpm": 3400,
    "weight_g": 7150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 130 x 230 x 40 mm, NTN 7226B sits in the medium-duty 7200 single-row family of the angular-contact programme. Reading the code: 72 is the single-row dimension series (medium-duty 7200 single-row family), 26 encodes the 130 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The radial section height here is 50.0 mm, and the catalogue couples that with C 196 kN / C0 180 kN. Size selection is usually finished by checking that the C0 of 180 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 130 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "The 2,500 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The C0 of 180 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 196/180 kN ratings and 10 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7226B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7226B?",
        "a": "7226B is a single-row angular contact ball bearing to ISO 15: 130 mm bore, 230 mm outside diameter, 40 mm width (5.118 x 9.055 x 1.575 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 196 kN, C0 180 kN and a 10 kN fatigue load limit Pu; the grease limiting speed is 2,500 r/min and the oil rating 3,400 r/min; mass about 7150 g."
      },
      {
        "q": "How is the 7226B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 26 encodes the 130 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 230 mm OD and 40 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7226B support?",
        "a": "One 7226B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7226B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,500 r/min and the oil rating 3,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7226B?",
        "a": "The 130/230/40 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 196 kN / C0 180 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7226B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7226b",
      "7226B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7326",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7326",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 130,
    "D_mm": 280,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 305,
    "static_load_kN": 293,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 16,
    "limiting_speed_rpm": 2700,
    "max_rpm": 2700,
    "speed_oil_rpm": 3600,
    "weight_g": 17600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 130 x 280 x 58 mm, NTN 7326 sits in the heavy-duty 7300 single-row family of the angular-contact programme. Reading the code: 73 is the single-row dimension series (heavy-duty 7300 single-row family), 26 encodes the 130 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue mass is about 17600 g, which at this 75.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. The 130/280/58 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 130 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "On a 130 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 305/293 kN ratings and 16 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7326; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7326?",
        "a": "7326 is a single-row angular contact ball bearing to ISO 15: 130 mm bore, 280 mm outside diameter, 58 mm width (5.118 x 11.024 x 2.283 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 305 kN, C0 293 kN and a 16 kN fatigue load limit Pu; the grease limiting speed is 2,700 r/min and the oil rating 3,600 r/min; mass about 17600 g."
      },
      {
        "q": "How is the 7326 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 26 encodes the 130 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 280 mm OD and 58 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7326 support?",
        "a": "One 7326 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7326?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,700 r/min and the oil rating 3,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7326?",
        "a": "The 130/280/58 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 305 kN / C0 293 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7326-BCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×280×58 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7326-BM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×280×58 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7326"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7326B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7326B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 130,
    "D_mm": 280,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 277,
    "static_load_kN": 268,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 14.7,
    "limiting_speed_rpm": 2300,
    "max_rpm": 2300,
    "speed_oil_rpm": 3100,
    "weight_g": 17600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7326B belongs to the heavy-duty 7300 single-row family: the catalogue boundary dimensions read 130 / 280 / 58 mm (bore / OD / width). NTN builds the number from 73 is the single-row dimension series (heavy-duty 7300 single-row family), then 26 encodes the 130 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Against a deep-groove bearing of the same 130 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 130 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 2,300 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 277/268 kN ratings and 14.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7326B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7326B?",
        "a": "7326B is a single-row angular contact ball bearing to ISO 15: 130 mm bore, 280 mm outside diameter, 58 mm width (5.118 x 11.024 x 2.283 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 277 kN, C0 268 kN and a 14.7 kN fatigue load limit Pu; the grease limiting speed is 2,300 r/min and the oil rating 3,100 r/min; mass about 17600 g."
      },
      {
        "q": "How is the 7326B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 26 encodes the 130 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 280 mm OD and 58 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7326B support?",
        "a": "One 7326B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7326B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,300 r/min and the oil rating 3,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7326B?",
        "a": "The 130/280/58 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 277 kN / C0 268 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7326B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7326b",
      "7326B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7928",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7928",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 140,
    "D_mm": 190,
    "B_mm": 24,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 83.5,
    "static_load_kN": 90,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 4.65,
    "limiting_speed_rpm": 3300,
    "max_rpm": 3300,
    "speed_oil_rpm": 4400,
    "weight_g": 1940,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the extra-light, high-speed 7900 single-row family, 7928 measures 140 mm across the bore, 190 mm over the outer ring and 24 mm across the faces. Decoding 7928: 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), with 28 encodes the 140 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. NTN prints 83.5 kN dynamic and 90 kN static for this size and a 4.65 kN fatigue load limit Pu. Against a deep-groove bearing of the same 140 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 140 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 90 kN really covers the worst static case before substituting it for a 7000.",
      "On a 140 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "On a 140 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7928 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 83.5/90 kN ratings and 4.65 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7928; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7928?",
        "a": "7928 is a single-row angular contact ball bearing to ISO 15: 140 mm bore, 190 mm outside diameter, 24 mm width (5.512 x 7.48 x 0.945 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 83.5 kN, C0 90 kN and a 4.65 kN fatigue load limit Pu; the grease limiting speed is 3,300 r/min and the oil rating 4,400 r/min; mass about 1940 g."
      },
      {
        "q": "How is the 7928 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 28 encodes the 140 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 190 mm OD and 24 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7928 support?",
        "a": "One 7928 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7928?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,300 r/min and the oil rating 4,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7928?",
        "a": "The 140/190/24 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 83.5 kN / C0 90 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7928",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7928"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7028",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7028",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 140,
    "D_mm": 210,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 133,
    "static_load_kN": 133,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 6.85,
    "limiting_speed_rpm": 3100,
    "max_rpm": 3100,
    "speed_oil_rpm": 4100,
    "weight_g": 3960,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7028 is an NTN single-row angular contact ball bearing: standard-section 7000 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 140 x 210 x 33 mm. Reading the code: 70 is the single-row dimension series (standard-section 7000 single-row family), 28 encodes the 140 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue mass is about 3960 g, which at this 35.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Choose the standard-section 7000 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 140 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A 7028 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 3,100 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 133/133 kN ratings and 6.85 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7028; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7028?",
        "a": "7028 is a single-row angular contact ball bearing to ISO 15: 140 mm bore, 210 mm outside diameter, 33 mm width (5.512 x 8.268 x 1.299 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 133 kN, C0 133 kN and a 6.85 kN fatigue load limit Pu; the grease limiting speed is 3,100 r/min and the oil rating 4,100 r/min; mass about 3960 g."
      },
      {
        "q": "How is the 7028 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 28 encodes the 140 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 210 mm OD and 33 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7028 support?",
        "a": "One 7028 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7028?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,100 r/min and the oil rating 4,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7028?",
        "a": "The 140/210/33 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 133 kN / C0 133 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7028-BGM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×210×33 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7028"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7228",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7228",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 140,
    "D_mm": 250,
    "B_mm": 42,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 225,
    "static_load_kN": 215,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 11.7,
    "limiting_speed_rpm": 2700,
    "max_rpm": 2700,
    "speed_oil_rpm": 3600,
    "weight_g": 8780,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 140 x 250 x 42 mm, NTN 7228 sits in the medium-duty 7200 single-row family of the angular-contact programme. NTN builds the number from 72 is the single-row dimension series (medium-duty 7200 single-row family), then 28 encodes the 140 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. Size selection is usually finished by checking that the C0 of 215 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Heat-mounting to 80-90 deg C is the clean route onto a 140 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 140 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 2,700 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 225/215 kN ratings and 11.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7228; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7228?",
        "a": "7228 is a single-row angular contact ball bearing to ISO 15: 140 mm bore, 250 mm outside diameter, 42 mm width (5.512 x 9.843 x 1.654 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 225 kN, C0 215 kN and a 11.7 kN fatigue load limit Pu; the grease limiting speed is 2,700 r/min and the oil rating 3,600 r/min; mass about 8780 g."
      },
      {
        "q": "How is the 7228 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 28 encodes the 140 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 250 mm OD and 42 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7228 support?",
        "a": "One 7228 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7228?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,700 r/min and the oil rating 3,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7228?",
        "a": "The 140/250/42 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 225 kN / C0 215 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7228-BCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×250×42 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      },
      {
        "equiv_sku": "7228-BM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×250×42 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7228"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7228B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7228B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 140,
    "D_mm": 250,
    "B_mm": 42,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 203,
    "static_load_kN": 195,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 10.1,
    "limiting_speed_rpm": 2300,
    "max_rpm": 2300,
    "speed_oil_rpm": 3100,
    "weight_g": 8780,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 7200 single-row family entry 7228B carries a 140 mm bore in a 250 mm outside diameter, 42 mm wide envelope. The designation breaks down as 72 is the single-row dimension series (medium-duty 7200 single-row family); 28 encodes the 140 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The static margin, C0 195 kN versus C 203 kN, is what supports slow oscillating duty and shock without immediate brinelling. Choose the medium-duty 7200 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 140 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Grease rated for deep-groove motor duty is not automatically right at 2,300 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7228B without re-checking axial float, heat and housing width — the kinematics differ.",
      "Do not pair two random 7228B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 203/195 kN ratings and 10.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7228B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7228B?",
        "a": "7228B is a single-row angular contact ball bearing to ISO 15: 140 mm bore, 250 mm outside diameter, 42 mm width (5.512 x 9.843 x 1.654 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 203 kN, C0 195 kN and a 10.1 kN fatigue load limit Pu; the grease limiting speed is 2,300 r/min and the oil rating 3,100 r/min; mass about 8780 g."
      },
      {
        "q": "How is the 7228B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 28 encodes the 140 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 250 mm OD and 42 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7228B support?",
        "a": "One 7228B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7228B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,300 r/min and the oil rating 3,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7228B?",
        "a": "The 140/250/42 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 203 kN / C0 195 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7228B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7228b",
      "7228B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7328",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7328",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 140,
    "D_mm": 300,
    "B_mm": 62,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 335,
    "static_load_kN": 335,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 17.7,
    "limiting_speed_rpm": 2500,
    "max_rpm": 2500,
    "speed_oil_rpm": 3300,
    "weight_g": 21500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty 7300 single-row family, 7328 measures 140 mm across the bore, 300 mm over the outer ring and 62 mm across the faces. Decoding 7328: 73 is the single-row dimension series (heavy-duty 7300 single-row family), with 28 encodes the 140 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 30 deg contact angle is the lever that turns the 335 kN static rating into useful one-direction thrust capacity. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Heat-mounting to 80-90 deg C is the clean route onto a 140 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 140 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7328 without re-checking axial float, heat and housing width — the kinematics differ.",
      "A 7328 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 335/335 kN ratings and 17.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7328; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7328?",
        "a": "7328 is a single-row angular contact ball bearing to ISO 15: 140 mm bore, 300 mm outside diameter, 62 mm width (5.512 x 11.811 x 2.441 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 335 kN, C0 335 kN and a 17.7 kN fatigue load limit Pu; the grease limiting speed is 2,500 r/min and the oil rating 3,300 r/min; mass about 21500 g."
      },
      {
        "q": "How is the 7328 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 28 encodes the 140 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 300 mm OD and 62 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7328 support?",
        "a": "One 7328 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7328?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,500 r/min and the oil rating 3,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7328?",
        "a": "The 140/300/62 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 335 kN / C0 335 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7328-BCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×300×62 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7328"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7328B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7328B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 140,
    "D_mm": 300,
    "B_mm": 62,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 305,
    "static_load_kN": 310,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 16.3,
    "limiting_speed_rpm": 2100,
    "max_rpm": 2100,
    "speed_oil_rpm": 2800,
    "weight_g": 21500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7328B appears as a heavy-duty 7300 single-row family bearing of 140 mm bore, 300 mm outside diameter and 62 mm width. Decoding 7328B: 73 is the single-row dimension series (heavy-duty 7300 single-row family), with 28 encodes the 140 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). On speed, the grease limiting speed is 2,100 r/min and the oil rating 2,800 r/min. For a 140 mm shaft with combined load, the practical shortlist is this series, its 7200-series lighter section, and — where thrust reverses — a back-to-back pair rather than a single row. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 140 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "The C0 of 310 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The C0 of 310 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 305/310 kN ratings and 16.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7328B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7328B?",
        "a": "7328B is a single-row angular contact ball bearing to ISO 15: 140 mm bore, 300 mm outside diameter, 62 mm width (5.512 x 11.811 x 2.441 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 305 kN, C0 310 kN and a 16.3 kN fatigue load limit Pu; the grease limiting speed is 2,100 r/min and the oil rating 2,800 r/min; mass about 21500 g."
      },
      {
        "q": "How is the 7328B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 28 encodes the 140 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 300 mm OD and 62 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7328B support?",
        "a": "One 7328B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7328B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,100 r/min and the oil rating 2,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7328B?",
        "a": "The 140/300/62 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 305 kN / C0 310 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7328B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7328b",
      "7328B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7930",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7930",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 150,
    "D_mm": 210,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 108,
    "static_load_kN": 117,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 5.8,
    "limiting_speed_rpm": 3100,
    "max_rpm": 3100,
    "speed_oil_rpm": 4100,
    "weight_g": 2960,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7930 appears as a extra-light, high-speed 7900 single-row family bearing of 150 mm bore, 210 mm outside diameter and 28 mm width. Two fields make up the code — 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family) and 30 encodes the 150 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. On speed, the grease limiting speed is 3,100 r/min and the oil rating 4,100 r/min. Choose the extra-light, high-speed 7900 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 150 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 117 kN really covers the worst static case before substituting it for a 7000.",
      "Grease rated for deep-groove motor duty is not automatically right at 3,100 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7930 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The C0 of 117 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 108/117 kN ratings and 5.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7930; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7930?",
        "a": "7930 is a single-row angular contact ball bearing to ISO 15: 150 mm bore, 210 mm outside diameter, 28 mm width (5.906 x 8.268 x 1.102 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 108 kN, C0 117 kN and a 5.8 kN fatigue load limit Pu; the grease limiting speed is 3,100 r/min and the oil rating 4,100 r/min; mass about 2960 g."
      },
      {
        "q": "How is the 7930 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 30 encodes the 150 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 210 mm OD and 28 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7930 support?",
        "a": "One 7930 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7930?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 3,100 r/min and the oil rating 4,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7930?",
        "a": "The 150/210/28 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 108 kN / C0 117 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7930",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7930"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7030",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7030",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 150,
    "D_mm": 225,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 152,
    "static_load_kN": 154,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 7.65,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "speed_oil_rpm": 3800,
    "weight_g": 4820,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7030 belongs to the standard-section 7000 single-row family: the catalogue boundary dimensions read 150 / 225 / 35 mm (bore / OD / width). The designation breaks down as 70 is the single-row dimension series (standard-section 7000 single-row family); 30 encodes the 150 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The static margin, C0 154 kN versus C 152 kN, is what supports slow oscillating duty and shock without immediate brinelling. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 150 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "On a 150 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "On a 150 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Do not pair two random 7030 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 152/154 kN ratings and 7.65 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7030; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7030?",
        "a": "7030 is a single-row angular contact ball bearing to ISO 15: 150 mm bore, 225 mm outside diameter, 35 mm width (5.906 x 8.858 x 1.378 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 152 kN, C0 154 kN and a 7.65 kN fatigue load limit Pu; the grease limiting speed is 2,800 r/min and the oil rating 3,800 r/min; mass about 4820 g."
      },
      {
        "q": "How is the 7030 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 30 encodes the 150 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 225 mm OD and 35 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7030 support?",
        "a": "One 7030 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7030?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,800 r/min and the oil rating 3,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7030?",
        "a": "The 150/225/35 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 152 kN / C0 154 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7030-BGM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×225×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7030"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7230",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7230",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 150,
    "D_mm": 270,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 257,
    "static_load_kN": 259,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 13.7,
    "limiting_speed_rpm": 2500,
    "max_rpm": 2500,
    "speed_oil_rpm": 3400,
    "weight_g": 11000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 7200 single-row family, 7230 measures 150 mm across the bore, 270 mm over the outer ring and 45 mm across the faces. Decoding 7230: 72 is the single-row dimension series (medium-duty 7200 single-row family), with 30 encodes the 150 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. With C 257 kN and C0 259 kN, each mm of bore carries about 1.71 kN of dynamic rating. The 150/270/45 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 150 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The 2,500 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Grease rated for deep-groove motor duty is not automatically right at 2,500 r/min with preload; check the grease speed factor against the catalogue figure.",
      "On a 150 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 257/259 kN ratings and 13.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7230; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7230?",
        "a": "7230 is a single-row angular contact ball bearing to ISO 15: 150 mm bore, 270 mm outside diameter, 45 mm width (5.906 x 10.63 x 1.772 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 257 kN, C0 259 kN and a 13.7 kN fatigue load limit Pu; the grease limiting speed is 2,500 r/min and the oil rating 3,400 r/min; mass about 11000 g."
      },
      {
        "q": "How is the 7230 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 30 encodes the 150 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 270 mm OD and 45 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7230 support?",
        "a": "One 7230 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7230?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,500 r/min and the oil rating 3,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7230?",
        "a": "The 150/270/45 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 257 kN / C0 259 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7230-BCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×270×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7230"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7230B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7230B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 150,
    "D_mm": 270,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 232,
    "static_load_kN": 235,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 11.9,
    "limiting_speed_rpm": 2200,
    "max_rpm": 2200,
    "speed_oil_rpm": 2900,
    "weight_g": 11000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7230B belongs to the medium-duty 7200 single-row family: the catalogue boundary dimensions read 150 / 270 / 45 mm (bore / OD / width). Decoding 7230B: 72 is the single-row dimension series (medium-duty 7200 single-row family), with 30 encodes the 150 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). On speed, the grease limiting speed is 2,200 r/min and the oil rating 2,900 r/min. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. A 150 mm shaft typically takes a m6/n6 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 150 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "The C0 of 235 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "On a 150 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The C0 of 235 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "The 232/235 kN ratings and 11.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7230B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7230B?",
        "a": "7230B is a single-row angular contact ball bearing to ISO 15: 150 mm bore, 270 mm outside diameter, 45 mm width (5.906 x 10.63 x 1.772 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 232 kN, C0 235 kN and a 11.9 kN fatigue load limit Pu; the grease limiting speed is 2,200 r/min and the oil rating 2,900 r/min; mass about 11000 g."
      },
      {
        "q": "How is the 7230B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 30 encodes the 150 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 270 mm OD and 45 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7230B support?",
        "a": "One 7230B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7230B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,200 r/min and the oil rating 2,900 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7230B?",
        "a": "The 150/270/45 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 232 kN / C0 235 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7230B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7230b",
      "7230B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7330",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7330",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 150,
    "D_mm": 320,
    "B_mm": 65,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 365,
    "static_load_kN": 380,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 19.5,
    "limiting_speed_rpm": 2300,
    "max_rpm": 2300,
    "speed_oil_rpm": 3100,
    "weight_g": 25100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7330 appears as a heavy-duty 7300 single-row family bearing of 150 mm bore, 320 mm outside diameter and 65 mm width. Two fields make up the code — 73 is the single-row dimension series (heavy-duty 7300 single-row family) and 30 encodes the 150 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue dynamic rating C is 365 kN against C0 380 kN — a C0/C ratio of 1.04 that is typical of an angular-contact contact ellipse. Against a deep-groove bearing of the same 150 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 150 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A 7330 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The C0 of 380 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 365/380 kN ratings and 19.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7330; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7330?",
        "a": "7330 is a single-row angular contact ball bearing to ISO 15: 150 mm bore, 320 mm outside diameter, 65 mm width (5.906 x 12.598 x 2.559 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 365 kN, C0 380 kN and a 19.5 kN fatigue load limit Pu; the grease limiting speed is 2,300 r/min and the oil rating 3,100 r/min; mass about 25100 g."
      },
      {
        "q": "How is the 7330 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 30 encodes the 150 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 320 mm OD and 65 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7330 support?",
        "a": "One 7330 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7330?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,300 r/min and the oil rating 3,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7330?",
        "a": "The 150/320/65 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 365 kN / C0 380 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7330-BCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7330"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7330B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7330B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 150,
    "D_mm": 320,
    "B_mm": 65,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 335,
    "static_load_kN": 350,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 17.9,
    "limiting_speed_rpm": 2000,
    "max_rpm": 2000,
    "speed_oil_rpm": 2600,
    "weight_g": 25100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7330B is an NTN single-row angular contact ball bearing: heavy-duty 7300 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 150 x 320 x 65 mm. Reading the code: 73 is the single-row dimension series (heavy-duty 7300 single-row family), 30 encodes the 150 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The static margin, C0 350 kN versus C 335 kN, is what supports slow oscillating duty and shock without immediate brinelling. Size selection is usually finished by checking that the C0 of 350 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 150 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 2,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Do not pair two random 7330B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 335/350 kN ratings and 17.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7330B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7330B?",
        "a": "7330B is a single-row angular contact ball bearing to ISO 15: 150 mm bore, 320 mm outside diameter, 65 mm width (5.906 x 12.598 x 2.559 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 335 kN, C0 350 kN and a 17.9 kN fatigue load limit Pu; the grease limiting speed is 2,000 r/min and the oil rating 2,600 r/min; mass about 25100 g."
      },
      {
        "q": "How is the 7330B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 30 encodes the 150 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 320 mm OD and 65 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7330B support?",
        "a": "One 7330B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7330B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,000 r/min and the oil rating 2,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7330B?",
        "a": "The 150/320/65 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 335 kN / C0 350 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7330B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7330b",
      "7330B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7932",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7932",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 160,
    "D_mm": 220,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 109,
    "static_load_kN": 121,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 5.8,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "speed_oil_rpm": 3800,
    "weight_g": 3130,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The extra-light, high-speed 7900 single-row family entry 7932 carries a 160 mm bore in a 220 mm outside diameter, 28 mm wide envelope. NTN builds the number from 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), then 32 encodes the 160 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The static margin, C0 121 kN versus C 109 kN, is what supports slow oscillating duty and shock without immediate brinelling. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 160 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 121 kN really covers the worst static case before substituting it for a 7000.",
      "Do not pair two random 7932 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The C0 of 121 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Do not pair two random 7932 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 109/121 kN ratings and 5.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7932; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7932?",
        "a": "7932 is a single-row angular contact ball bearing to ISO 15: 160 mm bore, 220 mm outside diameter, 28 mm width (6.299 x 8.661 x 1.102 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 109 kN, C0 121 kN and a 5.8 kN fatigue load limit Pu; the grease limiting speed is 2,800 r/min and the oil rating 3,800 r/min; mass about 3130 g."
      },
      {
        "q": "How is the 7932 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 32 encodes the 160 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 220 mm OD and 28 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7932 support?",
        "a": "One 7932 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7932?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,800 r/min and the oil rating 3,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7932?",
        "a": "The 160/220/28 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 109 kN / C0 121 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7932",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7932"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7032",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7032",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 160,
    "D_mm": 240,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 172,
    "static_load_kN": 176,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 8.55,
    "limiting_speed_rpm": 2700,
    "max_rpm": 2700,
    "speed_oil_rpm": 3600,
    "weight_g": 5960,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 160 x 240 x 38 mm, NTN 7032 sits in the standard-section 7000 single-row family of the angular-contact programme. Two fields make up the code — 70 is the single-row dimension series (standard-section 7000 single-row family) and 32 encodes the 160 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue dynamic rating C is 172 kN against C0 176 kN — a C0/C ratio of 1.02 that is typical of an angular-contact contact ellipse. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 160 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The C0 of 176 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7032 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 172/176 kN ratings and 8.55 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7032; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7032?",
        "a": "7032 is a single-row angular contact ball bearing to ISO 15: 160 mm bore, 240 mm outside diameter, 38 mm width (6.299 x 9.449 x 1.496 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 172 kN, C0 176 kN and a 8.55 kN fatigue load limit Pu; the grease limiting speed is 2,700 r/min and the oil rating 3,600 r/min; mass about 5960 g."
      },
      {
        "q": "How is the 7032 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 32 encodes the 160 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 240 mm OD and 38 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7032 support?",
        "a": "One 7032 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7032?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,700 r/min and the oil rating 3,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7032?",
        "a": "The 160/240/38 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 172 kN / C0 176 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7032",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7032"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7232",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7232",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 160,
    "D_mm": 290,
    "B_mm": 48,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 291,
    "static_load_kN": 305,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 15.8,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "speed_oil_rpm": 3200,
    "weight_g": 13700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7232 appears as a medium-duty 7200 single-row family bearing of 160 mm bore, 290 mm outside diameter and 48 mm width. The designation breaks down as 72 is the single-row dimension series (medium-duty 7200 single-row family); 32 encodes the 160 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The oil rating of 3,200 r/min sits 800 r/min above the 2,400 r/min grease figure — a 1.33x step that says how much headroom oil cooling buys. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Heat-mounting to 80-90 deg C is the clean route onto a 160 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 160 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7232 without re-checking axial float, heat and housing width — the kinematics differ.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Grease rated for deep-groove motor duty is not automatically right at 2,400 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 291/305 kN ratings and 15.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7232; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7232?",
        "a": "7232 is a single-row angular contact ball bearing to ISO 15: 160 mm bore, 290 mm outside diameter, 48 mm width (6.299 x 11.417 x 1.89 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 291 kN, C0 305 kN and a 15.8 kN fatigue load limit Pu; the grease limiting speed is 2,400 r/min and the oil rating 3,200 r/min; mass about 13700 g."
      },
      {
        "q": "How is the 7232 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 32 encodes the 160 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 290 mm OD and 48 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7232 support?",
        "a": "One 7232 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7232?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,400 r/min and the oil rating 3,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7232?",
        "a": "The 160/290/48 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 291 kN / C0 305 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7232-BCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×290×48 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7232"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7232B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7232B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 160,
    "D_mm": 290,
    "B_mm": 48,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 263,
    "static_load_kN": 279,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 13.7,
    "limiting_speed_rpm": 2000,
    "max_rpm": 2000,
    "speed_oil_rpm": 2700,
    "weight_g": 13700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7232B appears as a medium-duty 7200 single-row family bearing of 160 mm bore, 290 mm outside diameter and 48 mm width. Two fields make up the code — 72 is the single-row dimension series (medium-duty 7200 single-row family) and 32 encodes the 160 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Catalogue dynamic rating C is 263 kN against C0 279 kN — a C0/C ratio of 1.06 that is typical of an angular-contact contact ellipse. Size selection is usually finished by checking that the C0 of 279 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Grease quantity matters as much as grade at 2,000 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 160 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "The 2,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 2,000 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 263/279 kN ratings and 13.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7232B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7232B?",
        "a": "7232B is a single-row angular contact ball bearing to ISO 15: 160 mm bore, 290 mm outside diameter, 48 mm width (6.299 x 11.417 x 1.89 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 263 kN, C0 279 kN and a 13.7 kN fatigue load limit Pu; the grease limiting speed is 2,000 r/min and the oil rating 2,700 r/min; mass about 13700 g."
      },
      {
        "q": "How is the 7232B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 32 encodes the 160 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 290 mm OD and 48 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7232B support?",
        "a": "One 7232B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7232B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,000 r/min and the oil rating 2,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7232B?",
        "a": "The 160/290/48 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 263 kN / C0 279 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7232B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7232b",
      "7232B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7332",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7332",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 160,
    "D_mm": 340,
    "B_mm": 68,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 385,
    "static_load_kN": 420,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 20.9,
    "limiting_speed_rpm": 2100,
    "max_rpm": 2100,
    "speed_oil_rpm": 2800,
    "weight_g": 29800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The heavy-duty 7300 single-row family entry 7332 carries a 160 mm bore in a 340 mm outside diameter, 68 mm wide envelope. NTN builds the number from 73 is the single-row dimension series (heavy-duty 7300 single-row family), then 32 encodes the 160 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. NTN prints 385 kN dynamic and 420 kN static for this size and a 20.9 kN fatigue load limit Pu. The 160/340/68 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Heat-mounting to 80-90 deg C is the clean route onto a 160 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 160 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7332 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 385/420 kN ratings and 20.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7332; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7332?",
        "a": "7332 is a single-row angular contact ball bearing to ISO 15: 160 mm bore, 340 mm outside diameter, 68 mm width (6.299 x 13.386 x 2.677 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 385 kN, C0 420 kN and a 20.9 kN fatigue load limit Pu; the grease limiting speed is 2,100 r/min and the oil rating 2,800 r/min; mass about 29800 g."
      },
      {
        "q": "How is the 7332 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 32 encodes the 160 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 340 mm OD and 68 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7332 support?",
        "a": "One 7332 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7332?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,100 r/min and the oil rating 2,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7332?",
        "a": "The 160/340/68 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 385 kN / C0 420 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7332",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7332"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7332B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7332B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 160,
    "D_mm": 340,
    "B_mm": 68,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 350,
    "static_load_kN": 385,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 19.1,
    "limiting_speed_rpm": 1800,
    "max_rpm": 1800,
    "speed_oil_rpm": 2400,
    "weight_g": 29800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the heavy-duty 7300 single-row family, 7332B measures 160 mm across the bore, 340 mm over the outer ring and 68 mm across the faces. The designation breaks down as 73 is the single-row dimension series (heavy-duty 7300 single-row family); 32 encodes the 160 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). NTN prints 350 kN dynamic and 385 kN static for this size and a 19.1 kN fatigue load limit Pu. Choose the heavy-duty 7300 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 160 mm bore give the working limits. ",
    "applications": [
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 160 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Do not pair two random 7332B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7332B without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 350/385 kN ratings and 19.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7332B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7332B?",
        "a": "7332B is a single-row angular contact ball bearing to ISO 15: 160 mm bore, 340 mm outside diameter, 68 mm width (6.299 x 13.386 x 2.677 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 350 kN, C0 385 kN and a 19.1 kN fatigue load limit Pu; the grease limiting speed is 1,800 r/min and the oil rating 2,400 r/min; mass about 29800 g."
      },
      {
        "q": "How is the 7332B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 32 encodes the 160 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 340 mm OD and 68 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7332B support?",
        "a": "One 7332B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7332B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,800 r/min and the oil rating 2,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7332B?",
        "a": "The 160/340/68 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 350 kN / C0 385 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7332B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7332b",
      "7332B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7934",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7934",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 170,
    "D_mm": 230,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 115,
    "static_load_kN": 129,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 6.05,
    "limiting_speed_rpm": 2700,
    "max_rpm": 2700,
    "speed_oil_rpm": 3600,
    "weight_g": 3290,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7934 is the 170 mm bore member of NTN's extra-light, high-speed 7900 single-row family, with a 230 mm outside diameter and 28 mm section width. Reading the code: 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), 34 encodes the 170 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue dynamic rating C is 115 kN against C0 129 kN — a C0/C ratio of 1.12 that is typical of an angular-contact contact ellipse. Against a deep-groove bearing of the same 170 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 170 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 129 kN really covers the worst static case before substituting it for a 7000.",
      "On a 170 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 115/129 kN ratings and 6.05 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7934; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7934?",
        "a": "7934 is a single-row angular contact ball bearing to ISO 15: 170 mm bore, 230 mm outside diameter, 28 mm width (6.693 x 9.055 x 1.102 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 115 kN, C0 129 kN and a 6.05 kN fatigue load limit Pu; the grease limiting speed is 2,700 r/min and the oil rating 3,600 r/min; mass about 3290 g."
      },
      {
        "q": "How is the 7934 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 34 encodes the 170 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 230 mm OD and 28 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7934 support?",
        "a": "One 7934 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7934?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,700 r/min and the oil rating 3,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7934?",
        "a": "The 170/230/28 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 115 kN / C0 129 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7934",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7934"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7034",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7034",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 170,
    "D_mm": 260,
    "B_mm": 42,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 206,
    "static_load_kN": 214,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 10.2,
    "limiting_speed_rpm": 2500,
    "max_rpm": 2500,
    "speed_oil_rpm": 3300,
    "weight_g": 7960,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the standard-section 7000 single-row family, 7034 measures 170 mm across the bore, 260 mm over the outer ring and 42 mm across the faces. NTN builds the number from 70 is the single-row dimension series (standard-section 7000 single-row family), then 34 encodes the 170 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. NTN prints 206 kN dynamic and 214 kN static for this size and a 10.2 kN fatigue load limit Pu. Choose the standard-section 7000 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 170 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A 7034 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The C0 of 214 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7034 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 206/214 kN ratings and 10.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7034; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7034?",
        "a": "7034 is a single-row angular contact ball bearing to ISO 15: 170 mm bore, 260 mm outside diameter, 42 mm width (6.693 x 10.236 x 1.654 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 206 kN, C0 214 kN and a 10.2 kN fatigue load limit Pu; the grease limiting speed is 2,500 r/min and the oil rating 3,300 r/min; mass about 7960 g."
      },
      {
        "q": "How is the 7034 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 34 encodes the 170 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 260 mm OD and 42 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7034 support?",
        "a": "One 7034 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7034?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,500 r/min and the oil rating 3,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7034?",
        "a": "The 170/260/42 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 206 kN / C0 214 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7034-BGM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 170×260×42 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7034"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7234",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7234",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 170,
    "D_mm": 310,
    "B_mm": 52,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 325,
    "static_load_kN": 360,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 18,
    "limiting_speed_rpm": 2200,
    "max_rpm": 2200,
    "speed_oil_rpm": 3000,
    "weight_g": 17000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The medium-duty 7200 single-row family entry 7234 carries a 170 mm bore in a 310 mm outside diameter, 52 mm wide envelope. Two fields make up the code — 72 is the single-row dimension series (medium-duty 7200 single-row family) and 34 encodes the 170 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. At roughly 70.0 mm of radial section, the catalogue still quotes 325 kN dynamic capacity for the 170 mm bore. Size selection is usually finished by checking that the C0 of 360 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Grease quantity matters as much as grade at 2,200 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 170 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Do not pair two random 7234 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 325/360 kN ratings and 18 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7234; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7234?",
        "a": "7234 is a single-row angular contact ball bearing to ISO 15: 170 mm bore, 310 mm outside diameter, 52 mm width (6.693 x 12.205 x 2.047 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 325 kN, C0 360 kN and a 18 kN fatigue load limit Pu; the grease limiting speed is 2,200 r/min and the oil rating 3,000 r/min; mass about 17000 g."
      },
      {
        "q": "How is the 7234 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 34 encodes the 170 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 310 mm OD and 52 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7234 support?",
        "a": "One 7234 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7234?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,200 r/min and the oil rating 3,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7234?",
        "a": "The 170/310/52 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 325 kN / C0 360 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7234-BCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 170×310×52 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7234"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7234B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7234B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 170,
    "D_mm": 310,
    "B_mm": 52,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 295,
    "static_load_kN": 325,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 15.6,
    "limiting_speed_rpm": 1900,
    "max_rpm": 1900,
    "speed_oil_rpm": 2500,
    "weight_g": 17000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7234B is an NTN single-row angular contact ball bearing: medium-duty 7200 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 170 x 310 x 52 mm. Reading the code: 72 is the single-row dimension series (medium-duty 7200 single-row family), 34 encodes the 170 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Catalogue mass is about 17000 g, which at this 70.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Choose the medium-duty 7200 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Heat-mounting to 80-90 deg C is the clean route onto a 170 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 170 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Grease rated for deep-groove motor duty is not automatically right at 1,900 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Do not pair two random 7234B bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 295/325 kN ratings and 15.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7234B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7234B?",
        "a": "7234B is a single-row angular contact ball bearing to ISO 15: 170 mm bore, 310 mm outside diameter, 52 mm width (6.693 x 12.205 x 2.047 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 295 kN, C0 325 kN and a 15.6 kN fatigue load limit Pu; the grease limiting speed is 1,900 r/min and the oil rating 2,500 r/min; mass about 17000 g."
      },
      {
        "q": "How is the 7234B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 34 encodes the 170 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 310 mm OD and 52 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7234B support?",
        "a": "One 7234B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7234B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,900 r/min and the oil rating 2,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7234B?",
        "a": "The 170/310/52 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 295 kN / C0 325 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7234B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7234b",
      "7234B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7334",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7334",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 170,
    "D_mm": 360,
    "B_mm": 72,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 430,
    "static_load_kN": 485,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 23.3,
    "limiting_speed_rpm": 2000,
    "max_rpm": 2000,
    "speed_oil_rpm": 2700,
    "weight_g": 35300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7334 is the 170 mm bore member of NTN's heavy-duty 7300 single-row family, with a 360 mm outside diameter and 72 mm section width. Reading the code: 73 is the single-row dimension series (heavy-duty 7300 single-row family), 34 encodes the 170 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue mass is about 35300 g, which at this 95.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Grease quantity matters as much as grade at 2,000 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 170 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "A 7334 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 430/485 kN ratings and 23.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7334; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7334?",
        "a": "7334 is a single-row angular contact ball bearing to ISO 15: 170 mm bore, 360 mm outside diameter, 72 mm width (6.693 x 14.173 x 2.835 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 430 kN, C0 485 kN and a 23.3 kN fatigue load limit Pu; the grease limiting speed is 2,000 r/min and the oil rating 2,700 r/min; mass about 35300 g."
      },
      {
        "q": "How is the 7334 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 34 encodes the 170 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 360 mm OD and 72 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7334 support?",
        "a": "One 7334 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7334?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,000 r/min and the oil rating 2,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7334?",
        "a": "The 170/360/72 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 430 kN / C0 485 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7334-BCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 170×360×72 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=132",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7334"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7334B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7334B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 170,
    "D_mm": 360,
    "B_mm": 72,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 395,
    "static_load_kN": 445,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 21.3,
    "limiting_speed_rpm": 1700,
    "max_rpm": 1700,
    "speed_oil_rpm": 2300,
    "weight_g": 35300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7334B is the 170 mm bore member of NTN's heavy-duty 7300 single-row family, with a 360 mm outside diameter and 72 mm section width. NTN builds the number from 73 is the single-row dimension series (heavy-duty 7300 single-row family), then 34 encodes the 170 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 40 deg contact angle is the lever that turns the 445 kN static rating into useful one-direction thrust capacity. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. A 170 mm shaft typically takes a m6/n6 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 170 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "The C0 of 445 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "A 7334B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 395/445 kN ratings and 21.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7334B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7334B?",
        "a": "7334B is a single-row angular contact ball bearing to ISO 15: 170 mm bore, 360 mm outside diameter, 72 mm width (6.693 x 14.173 x 2.835 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 395 kN, C0 445 kN and a 21.3 kN fatigue load limit Pu; the grease limiting speed is 1,700 r/min and the oil rating 2,300 r/min; mass about 35300 g."
      },
      {
        "q": "How is the 7334B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 34 encodes the 170 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 360 mm OD and 72 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7334B support?",
        "a": "One 7334B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7334B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,700 r/min and the oil rating 2,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7334B?",
        "a": "The 170/360/72 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 395 kN / C0 445 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7334B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7334b",
      "7334B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7936",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7936",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 180,
    "D_mm": 250,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 145,
    "static_load_kN": 163,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 7.4,
    "limiting_speed_rpm": 2500,
    "max_rpm": 2500,
    "speed_oil_rpm": 3300,
    "weight_g": 4870,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7936 is an NTN single-row angular contact ball bearing: extra-light, high-speed 7900 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 180 x 250 x 33 mm. Decoding 7936: 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), with 36 encodes the 180 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. NTN prints 145 kN dynamic and 163 kN static for this size and a 7.4 kN fatigue load limit Pu. The 180/250/33 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Heat-mounting to 80-90 deg C is the clean route onto a 180 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 180 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 163 kN really covers the worst static case before substituting it for a 7000.",
      "The C0 of 163 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "A 7936 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7936 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 145/163 kN ratings and 7.4 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7936; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7936?",
        "a": "7936 is a single-row angular contact ball bearing to ISO 15: 180 mm bore, 250 mm outside diameter, 33 mm width (7.087 x 9.843 x 1.299 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 145 kN, C0 163 kN and a 7.4 kN fatigue load limit Pu; the grease limiting speed is 2,500 r/min and the oil rating 3,300 r/min; mass about 4870 g."
      },
      {
        "q": "How is the 7936 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 36 encodes the 180 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 250 mm OD and 33 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7936 support?",
        "a": "One 7936 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7936?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,500 r/min and the oil rating 3,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7936?",
        "a": "The 180/250/33 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 145 kN / C0 163 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7936",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7936"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7036",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7036",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 180,
    "D_mm": 280,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 242,
    "static_load_kN": 266,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 12.3,
    "limiting_speed_rpm": 2300,
    "max_rpm": 2300,
    "speed_oil_rpm": 3100,
    "weight_g": 10400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7036 appears as a standard-section 7000 single-row family bearing of 180 mm bore, 280 mm outside diameter and 46 mm width. Reading the code: 70 is the single-row dimension series (standard-section 7000 single-row family), 36 encodes the 180 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue mass is about 10400 g, which at this 50.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. If the duty is mainly high speed with modest thrust, the 7900-series cross-section is the lighter alternative; if thrust dominates, the 7300-series section carries more. Heat-mounting to 80-90 deg C is the clean route onto a 180 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 180 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 242/266 kN ratings and 12.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7036; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7036?",
        "a": "7036 is a single-row angular contact ball bearing to ISO 15: 180 mm bore, 280 mm outside diameter, 46 mm width (7.087 x 11.024 x 1.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 242 kN, C0 266 kN and a 12.3 kN fatigue load limit Pu; the grease limiting speed is 2,300 r/min and the oil rating 3,100 r/min; mass about 10400 g."
      },
      {
        "q": "How is the 7036 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 36 encodes the 180 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 280 mm OD and 46 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7036 support?",
        "a": "One 7036 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7036?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,300 r/min and the oil rating 3,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7036?",
        "a": "The 180/280/46 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 242 kN / C0 266 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7036-BGM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 180×280×46 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7036"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7236",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7236",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 180,
    "D_mm": 320,
    "B_mm": 52,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 340,
    "static_load_kN": 385,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 18.6,
    "limiting_speed_rpm": 2100,
    "max_rpm": 2100,
    "speed_oil_rpm": 2800,
    "weight_g": 17700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7236 is the 180 mm bore member of NTN's medium-duty 7200 single-row family, with a 320 mm outside diameter and 52 mm section width. NTN builds the number from 72 is the single-row dimension series (medium-duty 7200 single-row family), then 36 encodes the 180 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. For a 180 mm shaft with combined load, the practical shortlist is this series, its 7300-series heavier section, and — where thrust reverses — a back-to-back pair rather than a single row. A 180 mm shaft typically takes a m6/n6 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 180 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 2,100 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 2,100 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 340/385 kN ratings and 18.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7236; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7236?",
        "a": "7236 is a single-row angular contact ball bearing to ISO 15: 180 mm bore, 320 mm outside diameter, 52 mm width (7.087 x 12.598 x 2.047 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 340 kN, C0 385 kN and a 18.6 kN fatigue load limit Pu; the grease limiting speed is 2,100 r/min and the oil rating 2,800 r/min; mass about 17700 g."
      },
      {
        "q": "How is the 7236 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 36 encodes the 180 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 320 mm OD and 52 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7236 support?",
        "a": "One 7236 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7236?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,100 r/min and the oil rating 2,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7236?",
        "a": "The 180/320/52 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 340 kN / C0 385 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7236-BCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 180×320×52 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7236"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7236B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7236B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 180,
    "D_mm": 320,
    "B_mm": 52,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 305,
    "static_load_kN": 350,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 16.1,
    "limiting_speed_rpm": 1800,
    "max_rpm": 1800,
    "speed_oil_rpm": 2400,
    "weight_g": 17700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the medium-duty 7200 single-row family, 7236B measures 180 mm across the bore, 320 mm over the outer ring and 52 mm across the faces. The designation breaks down as 72 is the single-row dimension series (medium-duty 7200 single-row family); 36 encodes the 180 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). With C 305 kN and C0 350 kN, each mm of bore carries about 1.69 kN of dynamic rating. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 180 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "A 7236B mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "On a 180 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 305/350 kN ratings and 16.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7236B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7236B?",
        "a": "7236B is a single-row angular contact ball bearing to ISO 15: 180 mm bore, 320 mm outside diameter, 52 mm width (7.087 x 12.598 x 2.047 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 305 kN, C0 350 kN and a 16.1 kN fatigue load limit Pu; the grease limiting speed is 1,800 r/min and the oil rating 2,400 r/min; mass about 17700 g."
      },
      {
        "q": "How is the 7236B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 36 encodes the 180 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 320 mm OD and 52 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7236B support?",
        "a": "One 7236B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7236B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,800 r/min and the oil rating 2,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7236B?",
        "a": "The 180/320/52 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 305 kN / C0 350 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7236B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7236b",
      "7236B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7336",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7336",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 180,
    "D_mm": 380,
    "B_mm": 75,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 455,
    "static_load_kN": 535,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 24.9,
    "limiting_speed_rpm": 1900,
    "max_rpm": 1900,
    "speed_oil_rpm": 2500,
    "weight_g": 40900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7336 is an NTN single-row angular contact ball bearing: heavy-duty 7300 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 180 x 380 x 75 mm. Decoding 7336: 73 is the single-row dimension series (heavy-duty 7300 single-row family), with 36 encodes the 180 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 30 deg contact angle is the lever that turns the 535 kN static rating into useful one-direction thrust capacity. Size selection is usually finished by checking that the C0 of 535 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. A 180 mm shaft typically takes a m6/n6 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 180 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "The 1,900 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "A 7336 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 455/535 kN ratings and 24.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7336; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7336?",
        "a": "7336 is a single-row angular contact ball bearing to ISO 15: 180 mm bore, 380 mm outside diameter, 75 mm width (7.087 x 14.961 x 2.953 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 455 kN, C0 535 kN and a 24.9 kN fatigue load limit Pu; the grease limiting speed is 1,900 r/min and the oil rating 2,500 r/min; mass about 40900 g."
      },
      {
        "q": "How is the 7336 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 36 encodes the 180 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 380 mm OD and 75 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7336 support?",
        "a": "One 7336 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7336?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,900 r/min and the oil rating 2,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7336?",
        "a": "The 180/380/75 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 455 kN / C0 535 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7336-BCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 180×380×75 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7336"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7336B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7336B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 180,
    "D_mm": 380,
    "B_mm": 75,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 415,
    "static_load_kN": 490,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 22.8,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 2100,
    "weight_g": 40900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 180 x 380 x 75 mm, NTN 7336B sits in the heavy-duty 7300 single-row family of the angular-contact programme. Decoding 7336B: 73 is the single-row dimension series (heavy-duty 7300 single-row family), with 36 encodes the 180 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The oil rating of 2,100 r/min sits 500 r/min above the 1,600 r/min grease figure — a 1.31x step that says how much headroom oil cooling buys. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Grease quantity matters as much as grade at 1,600 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 180 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "The 1,600 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Grease rated for deep-groove motor duty is not automatically right at 1,600 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Grease rated for deep-groove motor duty is not automatically right at 1,600 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 415/490 kN ratings and 22.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7336B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7336B?",
        "a": "7336B is a single-row angular contact ball bearing to ISO 15: 180 mm bore, 380 mm outside diameter, 75 mm width (7.087 x 14.961 x 2.953 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 415 kN, C0 490 kN and a 22.8 kN fatigue load limit Pu; the grease limiting speed is 1,600 r/min and the oil rating 2,100 r/min; mass about 40900 g."
      },
      {
        "q": "How is the 7336B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 36 encodes the 180 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 380 mm OD and 75 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7336B support?",
        "a": "One 7336B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7336B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,600 r/min and the oil rating 2,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7336B?",
        "a": "The 180/380/75 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 415 kN / C0 490 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7336B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7336b",
      "7336B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7938",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7938",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 190,
    "D_mm": 260,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 147,
    "static_load_kN": 169,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 7.45,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "speed_oil_rpm": 3200,
    "weight_g": 5100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7938 belongs to the extra-light, high-speed 7900 single-row family: the catalogue boundary dimensions read 190 / 260 / 33 mm (bore / OD / width). The designation breaks down as 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 38 encodes the 190 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue mass is about 5100 g, which at this 35.0 mm radial section keeps the bearing comfortably inside high-speed spindle weight budgets. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Grease quantity matters as much as grade at 2,400 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 190 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 169 kN really covers the worst static case before substituting it for a 7000.",
      "A 7938 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 147/169 kN ratings and 7.45 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7938; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7938?",
        "a": "7938 is a single-row angular contact ball bearing to ISO 15: 190 mm bore, 260 mm outside diameter, 33 mm width (7.48 x 10.236 x 1.299 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 147 kN, C0 169 kN and a 7.45 kN fatigue load limit Pu; the grease limiting speed is 2,400 r/min and the oil rating 3,200 r/min; mass about 5100 g."
      },
      {
        "q": "How is the 7938 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 38 encodes the 190 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 260 mm OD and 33 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7938 support?",
        "a": "One 7938 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7938?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,400 r/min and the oil rating 3,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7938?",
        "a": "The 190/260/33 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 147 kN / C0 169 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7938",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7938"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7038",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7038",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 190,
    "D_mm": 290,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 248,
    "static_load_kN": 280,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 12.6,
    "limiting_speed_rpm": 2200,
    "max_rpm": 2200,
    "speed_oil_rpm": 2900,
    "weight_g": 10800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The standard-section 7000 single-row family entry 7038 carries a 190 mm bore in a 290 mm outside diameter, 46 mm wide envelope. Decoding 7038: 70 is the single-row dimension series (standard-section 7000 single-row family), with 38 encodes the 190 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 30 deg contact angle is the lever that turns the 280 kN static rating into useful one-direction thrust capacity. Against a deep-groove bearing of the same 190 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Grease quantity matters as much as grade at 2,200 r/min: fill about a third of the free space and let the bearing purge on first run. ",
    "applications": [
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 190 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "A 7038 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "A 7038 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 248/280 kN ratings and 12.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7038; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7038?",
        "a": "7038 is a single-row angular contact ball bearing to ISO 15: 190 mm bore, 290 mm outside diameter, 46 mm width (7.48 x 11.417 x 1.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 248 kN, C0 280 kN and a 12.6 kN fatigue load limit Pu; the grease limiting speed is 2,200 r/min and the oil rating 2,900 r/min; mass about 10800 g."
      },
      {
        "q": "How is the 7038 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 38 encodes the 190 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 290 mm OD and 46 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7038 support?",
        "a": "One 7038 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7038?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,200 r/min and the oil rating 2,900 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7038?",
        "a": "The 190/290/46 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 248 kN / C0 280 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7038-BGM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 190×290×46 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7038"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7238",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7238",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 190,
    "D_mm": 340,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 335,
    "static_load_kN": 390,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 17.9,
    "limiting_speed_rpm": 2000,
    "max_rpm": 2000,
    "speed_oil_rpm": 2600,
    "weight_g": 21300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7238 is an NTN single-row angular contact ball bearing: medium-duty 7200 single-row family, listed in NTN Ball and Roller Bearings CAT.No.2203E at 190 x 340 x 55 mm. Reading the code: 72 is the single-row dimension series (medium-duty 7200 single-row family), 38 encodes the 190 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The radial section height here is 75.0 mm, and the catalogue couples that with C 335 kN / C0 390 kN. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 190 mm bore give the working limits. ",
    "applications": [
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 190 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Grease rated for deep-groove motor duty is not automatically right at 2,000 r/min with preload; check the grease speed factor against the catalogue figure.",
      "On a 190 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 335/390 kN ratings and 17.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7238; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7238?",
        "a": "7238 is a single-row angular contact ball bearing to ISO 15: 190 mm bore, 340 mm outside diameter, 55 mm width (7.48 x 13.386 x 2.165 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 335 kN, C0 390 kN and a 17.9 kN fatigue load limit Pu; the grease limiting speed is 2,000 r/min and the oil rating 2,600 r/min; mass about 21300 g."
      },
      {
        "q": "How is the 7238 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 38 encodes the 190 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 340 mm OD and 55 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7238 support?",
        "a": "One 7238 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7238?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,000 r/min and the oil rating 2,600 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7238?",
        "a": "The 190/340/55 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 335 kN / C0 390 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7238-BCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7238"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7238B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7238B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 190,
    "D_mm": 340,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 300,
    "static_load_kN": 355,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 15.5,
    "limiting_speed_rpm": 1700,
    "max_rpm": 1700,
    "speed_oil_rpm": 2200,
    "weight_g": 21300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7238B is the 190 mm bore member of NTN's medium-duty 7200 single-row family, with a 340 mm outside diameter and 55 mm section width. NTN builds the number from 72 is the single-row dimension series (medium-duty 7200 single-row family), then 38 encodes the 190 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). At roughly 75.0 mm of radial section, the catalogue still quotes 300 kN dynamic capacity for the 190 mm bore. Where the same envelope must also be sealed, or where mounting mistakes are likely, compare with the double-row 52/53 catalogue pages before fixing the bill of materials. Set preload or end-play with the pair as a unit and lock the adjustment; a single angular-contact bearing cannot run free like a deep-groove one. ",
    "applications": [
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 190 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7238B without re-checking axial float, heat and housing width — the kinematics differ.",
      "Grease rated for deep-groove motor duty is not automatically right at 1,700 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 300/355 kN ratings and 15.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7238B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7238B?",
        "a": "7238B is a single-row angular contact ball bearing to ISO 15: 190 mm bore, 340 mm outside diameter, 55 mm width (7.48 x 13.386 x 2.165 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 300 kN, C0 355 kN and a 15.5 kN fatigue load limit Pu; the grease limiting speed is 1,700 r/min and the oil rating 2,200 r/min; mass about 21300 g."
      },
      {
        "q": "How is the 7238B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 38 encodes the 190 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 340 mm OD and 55 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7238B support?",
        "a": "One 7238B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7238B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,700 r/min and the oil rating 2,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7238B?",
        "a": "The 190/340/55 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 300 kN / C0 355 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7238B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7238b",
      "7238B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7338",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7338",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 190,
    "D_mm": 400,
    "B_mm": 78,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 475,
    "static_load_kN": 585,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 26.6,
    "limiting_speed_rpm": 1800,
    "max_rpm": 1800,
    "speed_oil_rpm": 2300,
    "weight_g": 47000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7338 belongs to the heavy-duty 7300 single-row family: the catalogue boundary dimensions read 190 / 400 / 78 mm (bore / OD / width). The designation breaks down as 73 is the single-row dimension series (heavy-duty 7300 single-row family); 38 encodes the 190 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. With C 475 kN and C0 585 kN, each mm of bore carries about 2.50 kN of dynamic rating. For a 190 mm shaft with combined load, the practical shortlist is this series, its 7200-series lighter section, and — where thrust reverses — a back-to-back pair rather than a single row. Shaft and housing shoulders must clear the ring corners yet support enough face — the catalogue abutment diameters for the 190 mm bore give the working limits. ",
    "applications": [
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 190 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7338 without re-checking axial float, heat and housing width — the kinematics differ.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "On a 190 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "The 475/585 kN ratings and 26.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7338; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7338?",
        "a": "7338 is a single-row angular contact ball bearing to ISO 15: 190 mm bore, 400 mm outside diameter, 78 mm width (7.48 x 15.748 x 3.071 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 475 kN, C0 585 kN and a 26.6 kN fatigue load limit Pu; the grease limiting speed is 1,800 r/min and the oil rating 2,300 r/min; mass about 47000 g."
      },
      {
        "q": "How is the 7338 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 38 encodes the 190 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 400 mm OD and 78 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7338 support?",
        "a": "One 7338 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7338?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,800 r/min and the oil rating 2,300 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7338?",
        "a": "The 190/400/78 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 475 kN / C0 585 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7338-BCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7338"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7338B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7338B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 190,
    "D_mm": 400,
    "B_mm": 78,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 430,
    "static_load_kN": 535,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 24,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 2000,
    "weight_g": 47000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The heavy-duty 7300 single-row family entry 7338B carries a 190 mm bore in a 400 mm outside diameter, 78 mm wide envelope. Two fields make up the code — 73 is the single-row dimension series (heavy-duty 7300 single-row family) and 38 encodes the 190 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. The 190/400/78 envelope is an ISO 15 boundary plan, so dimensional interchange with other makers holds — ratings and internal geometry do not automatically follow. Heat-mounting to 80-90 deg C is the clean route onto a 190 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 190 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Grease rated for deep-groove motor duty is not automatically right at 1,500 r/min with preload; check the grease speed factor against the catalogue figure.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "The 1,500 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 430/535 kN ratings and 24 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7338B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7338B?",
        "a": "7338B is a single-row angular contact ball bearing to ISO 15: 190 mm bore, 400 mm outside diameter, 78 mm width (7.48 x 15.748 x 3.071 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 430 kN, C0 535 kN and a 24 kN fatigue load limit Pu; the grease limiting speed is 1,500 r/min and the oil rating 2,000 r/min; mass about 47000 g."
      },
      {
        "q": "How is the 7338B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 38 encodes the 190 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 400 mm OD and 78 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7338B support?",
        "a": "One 7338B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7338B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,500 r/min and the oil rating 2,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7338B?",
        "a": "The 190/400/78 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 430 kN / C0 535 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7338B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7338b",
      "7338B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7940",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7940",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 200,
    "D_mm": 280,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 205,
    "static_load_kN": 231,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 9.9,
    "limiting_speed_rpm": 2200,
    "max_rpm": 2200,
    "speed_oil_rpm": 3000,
    "weight_g": 7150,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 200 x 280 x 38 mm, NTN 7940 sits in the extra-light, high-speed 7900 single-row family of the angular-contact programme. NTN builds the number from 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), then 40 encodes the 200 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The static margin, C0 231 kN versus C 205 kN, is what supports slow oscillating duty and shock without immediate brinelling. Against a deep-groove bearing of the same 200 mm bore, this bearing trades some pure-radial comfort for real one-direction thrust capacity and higher running accuracy. Heat-mounting to 80-90 deg C is the clean route onto a 200 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 200 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 231 kN really covers the worst static case before substituting it for a 7000.",
      "On a 200 mm shaft, an interference fit eats internal clearance; skipping the clearance/preload recalculation is the classic cause of a new bearing running 20 deg C hotter than the drawing suggests.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Do not pair two random 7940 bearings from stock and expect catalogue paired ratings — matched-set grinding is what makes DB/DF/DT preload behave, and NTN sells those as separate order numbers.",
      "The 205/231 kN ratings and 9.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7940; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7940?",
        "a": "7940 is a single-row angular contact ball bearing to ISO 15: 200 mm bore, 280 mm outside diameter, 38 mm width (7.874 x 11.024 x 1.496 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 205 kN, C0 231 kN and a 9.9 kN fatigue load limit Pu; the grease limiting speed is 2,200 r/min and the oil rating 3,000 r/min; mass about 7150 g."
      },
      {
        "q": "How is the 7940 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 40 encodes the 200 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 280 mm OD and 38 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7940 support?",
        "a": "One 7940 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7940?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,200 r/min and the oil rating 3,000 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7940?",
        "a": "The 200/280/38 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 205 kN / C0 231 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7940",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7940"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7040",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7040",
    "series": "7000-series",
    "type": "angular_contact",
    "d_mm": 200,
    "D_mm": 310,
    "B_mm": 51,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 279,
    "static_load_kN": 325,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 14.3,
    "limiting_speed_rpm": 2100,
    "max_rpm": 2100,
    "speed_oil_rpm": 2800,
    "weight_g": 14000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7040 is the 200 mm bore member of NTN's standard-section 7000 single-row family, with a 310 mm outside diameter and 51 mm section width. Two fields make up the code — 70 is the single-row dimension series (standard-section 7000 single-row family) and 40 encodes the 200 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue dynamic rating C is 279 kN against C0 325 kN — a C0/C ratio of 1.16 that is typical of an angular-contact contact ellipse. Choose the standard-section 7000 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Heat-mounting to 80-90 deg C is the clean route onto a 200 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it. ",
    "applications": [
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 200 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "A 7040 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "The 279/325 kN ratings and 14.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7040; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7040?",
        "a": "7040 is a single-row angular contact ball bearing to ISO 15: 200 mm bore, 310 mm outside diameter, 51 mm width (7.874 x 12.205 x 2.008 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 279 kN, C0 325 kN and a 14.3 kN fatigue load limit Pu; the grease limiting speed is 2,100 r/min and the oil rating 2,800 r/min; mass about 14000 g."
      },
      {
        "q": "How is the 7040 designation structured?",
        "a": "70 is the single-row dimension series (standard-section 7000 single-row family); 40 encodes the 200 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 310 mm OD and 51 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7040 support?",
        "a": "One 7040 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7040?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,100 r/min and the oil rating 2,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7040?",
        "a": "The 200/310/51 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 279 kN / C0 325 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7040-BGM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 200×310×51 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7040"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7240",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7240",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 200,
    "D_mm": 360,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 375,
    "static_load_kN": 450,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 20.2,
    "limiting_speed_rpm": 1900,
    "max_rpm": 1900,
    "speed_oil_rpm": 2500,
    "weight_g": 25300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7240 belongs to the medium-duty 7200 single-row family: the catalogue boundary dimensions read 200 / 360 / 58 mm (bore / OD / width). The designation breaks down as 72 is the single-row dimension series (medium-duty 7200 single-row family); 40 encodes the 200 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The oil rating of 2,500 r/min sits 600 r/min above the 1,900 r/min grease figure — a 1.32x step that says how much headroom oil cooling buys. Size selection is usually finished by checking that the C0 of 450 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. A 200 mm shaft typically takes a m6/n6 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 200 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7240 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Grease rated for deep-groove motor duty is not automatically right at 1,900 r/min with preload; check the grease speed factor against the catalogue figure.",
      "The 375/450 kN ratings and 20.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7240; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7240?",
        "a": "7240 is a single-row angular contact ball bearing to ISO 15: 200 mm bore, 360 mm outside diameter, 58 mm width (7.874 x 14.173 x 2.283 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 375 kN, C0 450 kN and a 20.2 kN fatigue load limit Pu; the grease limiting speed is 1,900 r/min and the oil rating 2,500 r/min; mass about 25300 g."
      },
      {
        "q": "How is the 7240 designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 40 encodes the 200 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 360 mm OD and 58 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7240 support?",
        "a": "One 7240 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7240?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,900 r/min and the oil rating 2,500 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7240?",
        "a": "The 200/360/58 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 375 kN / C0 450 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7240-BCBM",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 200×360×58 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7240"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7240B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7240B",
    "series": "7200-series",
    "type": "angular_contact",
    "d_mm": 200,
    "D_mm": 360,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 335,
    "static_load_kN": 410,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 17.6,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 2100,
    "weight_g": 25300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 200 x 360 x 58 mm, NTN 7240B sits in the medium-duty 7200 single-row family of the angular-contact programme. Two fields make up the code — 72 is the single-row dimension series (medium-duty 7200 single-row family) and 40 encodes the 200 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). Because the contact line is angled, one bearing of this type takes radial load plus thrust from one direction only — the opposite direction needs a second bearing or a matched set. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 200 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "Grease rated for deep-groove motor duty is not automatically right at 1,600 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7240B without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 1,600 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "The 335/410 kN ratings and 17.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7240B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7240B?",
        "a": "7240B is a single-row angular contact ball bearing to ISO 15: 200 mm bore, 360 mm outside diameter, 58 mm width (7.874 x 14.173 x 2.283 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 335 kN, C0 410 kN and a 17.6 kN fatigue load limit Pu; the grease limiting speed is 1,600 r/min and the oil rating 2,100 r/min; mass about 25300 g."
      },
      {
        "q": "How is the 7240B designation structured?",
        "a": "72 is the single-row dimension series (medium-duty 7200 single-row family); 40 encodes the 200 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 360 mm OD and 58 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7240B support?",
        "a": "One 7240B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7240B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,600 r/min and the oil rating 2,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7240B?",
        "a": "The 200/360/58 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 335 kN / C0 410 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7240B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7240b",
      "7240B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7340",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7340",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 200,
    "D_mm": 420,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 500,
    "static_load_kN": 610,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 27,
    "limiting_speed_rpm": 1700,
    "max_rpm": 1700,
    "speed_oil_rpm": 2200,
    "weight_g": 53100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "At 200 x 420 x 80 mm, NTN 7340 sits in the heavy-duty 7300 single-row family of the angular-contact programme. NTN builds the number from 73 is the single-row dimension series (heavy-duty 7300 single-row family), then 40 encodes the 200 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. NTN prints 500 kN dynamic and 610 kN static for this size and a 27 kN fatigue load limit Pu. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. A 200 mm shaft typically takes a m6/n6 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 200 mm bore bearing forgives nothing in a poorly machined housing.",
      "The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Grease rated for deep-groove motor duty is not automatically right at 1,700 r/min with preload; check the grease speed factor against the catalogue figure.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7340 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 500/610 kN ratings and 27 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7340; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7340?",
        "a": "7340 is a single-row angular contact ball bearing to ISO 15: 200 mm bore, 420 mm outside diameter, 80 mm width (7.874 x 16.535 x 3.15 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 500 kN, C0 610 kN and a 27 kN fatigue load limit Pu; the grease limiting speed is 1,700 r/min and the oil rating 2,200 r/min; mass about 53100 g."
      },
      {
        "q": "How is the 7340 designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 40 encodes the 200 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 420 mm OD and 80 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7340 support?",
        "a": "One 7340 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7340?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,700 r/min and the oil rating 2,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7340?",
        "a": "The 200/420/80 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 500 kN / C0 610 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7340-BCBM",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7340"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7340B",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7340B",
    "series": "7300-series",
    "type": "angular_contact",
    "d_mm": 200,
    "D_mm": 420,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 455,
    "static_load_kN": 555,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 24.7,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1900,
    "weight_g": 53100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7340B belongs to the heavy-duty 7300 single-row family: the catalogue boundary dimensions read 200 / 420 / 80 mm (bore / OD / width). The designation breaks down as 73 is the single-row dimension series (heavy-duty 7300 single-row family); 40 encodes the 200 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). At roughly 110.0 mm of radial section, the catalogue still quotes 455 kN dynamic capacity for the 200 mm bore. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 200 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 40 deg B-execution raises axial capacity but lowers the speed ceiling — do not copy the standard-bearing speed and preload settings onto it.",
      "The C0 of 555 kN is a static rating, not a permissible running thrust — sizing continuous axial load from C0 alone is a recurring drawing-office error.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "The 455/555 kN ratings and 24.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7340B; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7340B?",
        "a": "7340B is a single-row angular contact ball bearing to ISO 15: 200 mm bore, 420 mm outside diameter, 80 mm width (7.874 x 16.535 x 3.15 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 455 kN, C0 555 kN and a 24.7 kN fatigue load limit Pu; the grease limiting speed is 1,400 r/min and the oil rating 1,900 r/min; mass about 53100 g."
      },
      {
        "q": "How is the 7340B designation structured?",
        "a": "73 is the single-row dimension series (heavy-duty 7300 single-row family); 40 encodes the 200 mm bore (bore code x 5), and the trailing B marks the 40 deg contact-angle execution (the no-letter standard bearing works at 30 deg). The 420 mm OD and 80 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7340B support?",
        "a": "One 7340B alone takes thrust in one direction only, along its 40 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7340B?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,400 r/min and the oil rating 1,900 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7340B?",
        "a": "The 200/420/80 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 455 kN / C0 555 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7340B",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7340b",
      "7340B"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7944",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7944",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 220,
    "D_mm": 300,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 207,
    "static_load_kN": 239,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 9.85,
    "limiting_speed_rpm": 2000,
    "max_rpm": 2000,
    "speed_oil_rpm": 2700,
    "weight_g": 7740,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 7944 appears as a extra-light, high-speed 7900 single-row family bearing of 220 mm bore, 300 mm outside diameter and 38 mm width. Decoding 7944: 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), with 44 encodes the 220 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. NTN prints 207 kN dynamic and 239 kN static for this size and a 9.85 kN fatigue load limit Pu. Selection starts from the thrust share: as axial load grows past roughly half the radial load, an angular-contact position of this section usually outlives a deep-groove one. A 220 mm shaft typically takes a m6/n6 fit for rotating inner-ring load; keep the housing bore to G6/H6 class so the contact geometry is not distorted. ",
    "applications": [
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 220 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 239 kN really covers the worst static case before substituting it for a 7000.",
      "A 7944 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7944 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 207/239 kN ratings and 9.85 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7944; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7944?",
        "a": "7944 is a single-row angular contact ball bearing to ISO 15: 220 mm bore, 300 mm outside diameter, 38 mm width (8.661 x 11.811 x 1.496 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 207 kN, C0 239 kN and a 9.85 kN fatigue load limit Pu; the grease limiting speed is 2,000 r/min and the oil rating 2,700 r/min; mass about 7740 g."
      },
      {
        "q": "How is the 7944 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 44 encodes the 220 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 300 mm OD and 38 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7944 support?",
        "a": "One 7944 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7944?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,000 r/min and the oil rating 2,700 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7944?",
        "a": "The 220/300/38 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 207 kN / C0 239 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7944",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7944"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7948",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7948",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 240,
    "D_mm": 320,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 213,
    "static_load_kN": 255,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 10.1,
    "limiting_speed_rpm": 1800,
    "max_rpm": 1800,
    "speed_oil_rpm": 2400,
    "weight_g": 8340,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "7948 is the 240 mm bore member of NTN's extra-light, high-speed 7900 single-row family, with a 320 mm outside diameter and 38 mm section width. Two fields make up the code — 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family) and 48 encodes the 240 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 30 deg contact angle is the lever that turns the 255 kN static rating into useful one-direction thrust capacity. For a 240 mm shaft with combined load, the practical shortlist is this series, its 7000-series standard section, and — where thrust reverses — a back-to-back pair rather than a single row. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 240 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 255 kN really covers the worst static case before substituting it for a 7000.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "The 1,800 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "A 7948 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 213/255 kN ratings and 10.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7948; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7948?",
        "a": "7948 is a single-row angular contact ball bearing to ISO 15: 240 mm bore, 320 mm outside diameter, 38 mm width (9.449 x 12.598 x 1.496 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 213 kN, C0 255 kN and a 10.1 kN fatigue load limit Pu; the grease limiting speed is 1,800 r/min and the oil rating 2,400 r/min; mass about 8340 g."
      },
      {
        "q": "How is the 7948 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 48 encodes the 240 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 320 mm OD and 38 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7948 support?",
        "a": "One 7948 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7948?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,800 r/min and the oil rating 2,400 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7948?",
        "a": "The 240/320/38 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 213 kN / C0 255 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7948",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7948"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7952",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7952",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 260,
    "D_mm": 360,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 285,
    "static_load_kN": 375,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 14.1,
    "limiting_speed_rpm": 1700,
    "max_rpm": 1700,
    "speed_oil_rpm": 2200,
    "weight_g": 14000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "NTN 7952 belongs to the extra-light, high-speed 7900 single-row family: the catalogue boundary dimensions read 260 / 360 / 46 mm (bore / OD / width). Decoding 7952: 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), with 52 encodes the 260 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. NTN prints 285 kN dynamic and 375 kN static for this size and a 14.1 kN fatigue load limit Pu. Size selection is usually finished by checking that the C0 of 375 kN covers the maximum static or shock condition with the catalogue safety factor, not only the running load. Mount with the thrust against the marked face: the contact angle runs from the low shoulder of the inner ring to the high shoulder of the outer ring, and reversing it throws the capacity away. ",
    "applications": [
      "large fan, blower and turbo-compressor rotors",
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "resin-cage cracking on the 7900-series sizes after hot, dry running or solvent attack on the polymer",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 260 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 375 kN really covers the worst static case before substituting it for a 7000.",
      "A single-row angular contact left loose on the shaft to \"help assembly\" will fret the seat: the contact angle keeps driving the ring axially under load.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7952 without re-checking axial float, heat and housing width — the kinematics differ.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7952 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 285/375 kN ratings and 14.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7952; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7952?",
        "a": "7952 is a single-row angular contact ball bearing to ISO 15: 260 mm bore, 360 mm outside diameter, 46 mm width (10.236 x 14.173 x 1.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 285 kN, C0 375 kN and a 14.1 kN fatigue load limit Pu; the grease limiting speed is 1,700 r/min and the oil rating 2,200 r/min; mass about 14000 g."
      },
      {
        "q": "How is the 7952 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 52 encodes the 260 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 360 mm OD and 46 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7952 support?",
        "a": "One 7952 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7952?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,700 r/min and the oil rating 2,200 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7952?",
        "a": "The 260/360/46 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 285 kN / C0 375 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7952",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7952"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7956",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7956",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 280,
    "D_mm": 380,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 289,
    "static_load_kN": 385,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 14.1,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 2100,
    "weight_g": 14800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "From the extra-light, high-speed 7900 single-row family, 7956 measures 280 mm across the bore, 380 mm over the outer ring and 46 mm across the faces. Two fields make up the code — 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family) and 56 encodes the 280 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 30 deg contact angle is the lever that turns the 385 kN static rating into useful one-direction thrust capacity. When axial load reverses, specify the bearing as a matched pair (DB, DF or DT) instead of two random singles — the catalogue right-hand columns give the paired ratings for exactly this reason. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "rolling-mill backup and drive spindles",
      "crusher and mill pinion shafts",
      "large pump and turbine auxiliary shafts",
      "steel-plant conveyor and table roll drives"
    ],
    "failure_modes": [
      "false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch",
      "thermal runaway from excessive preload: the pair runs hot, grease darkens and the contact ellipse spreads until the raceways smear",
      "machined-cage land scoring when a high-speed spindle runs past its grease rating and the cage runs dry on its guidance surface",
      "lubricant starvation scoring at the ball/raceway contact when grease volume or relubrication interval is guessed instead of calculated",
      "contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 280 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 385 kN really covers the worst static case before substituting it for a 7000.",
      "The 1,500 r/min speed figure assumes the catalogue lubrication state and a correctly set pair; real limits drop fast with excess grease fill or heavy preload.",
      "Catalogue mass and ratings belong to the open execution; shields, seals and resin cages change both the speed ceiling and the thermal behaviour of the same basic size.",
      "A 7956 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.",
      "The 289/385 kN ratings and 14.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7956; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7956?",
        "a": "7956 is a single-row angular contact ball bearing to ISO 15: 280 mm bore, 380 mm outside diameter, 46 mm width (11.024 x 14.961 x 1.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 289 kN, C0 385 kN and a 14.1 kN fatigue load limit Pu; the grease limiting speed is 1,500 r/min and the oil rating 2,100 r/min; mass about 14800 g."
      },
      {
        "q": "How is the 7956 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 56 encodes the 280 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 380 mm OD and 46 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7956 support?",
        "a": "One 7956 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7956?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,500 r/min and the oil rating 2,100 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7956?",
        "a": "The 280/380/46 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 289 kN / C0 385 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7956",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7956"
    ],
    "locale_variants": {}
  },
  {
    "sku": "7960",
    "brand": "NTN",
    "manufacturer_designation": "NTN 7960",
    "series": "7900-series",
    "type": "angular_contact",
    "d_mm": 300,
    "D_mm": 420,
    "B_mm": 56,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 360,
    "static_load_kN": 520,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 18.2,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1900,
    "weight_g": 23700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "The extra-light, high-speed 7900 single-row family entry 7960 carries a 300 mm bore in a 420 mm outside diameter, 56 mm wide envelope. Decoding 7960: 79 is the single-row dimension series (extra-light, high-speed 7900 single-row family), with 60 encodes the 300 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. NTN prints 360 kN dynamic and 520 kN static for this size and a 18.2 kN fatigue load limit Pu. For a 300 mm shaft with combined load, the practical shortlist is this series, its 7000-series standard section, and — where thrust reverses — a back-to-back pair rather than a single row. After mounting, check axial float or preload with a dial gauge on the shaft end — the specification, not hand feel, decides whether the contact angle works as rated. ",
    "applications": [
      "steel-plant conveyor and table roll drives",
      "wind-turbine and heavy-machinery auxiliaries",
      "heavy industrial gearbox main shafts",
      "large fan, blower and turbo-compressor rotors"
    ],
    "failure_modes": [
      "impact brinelling dents on the 30 deg contact path after a shaft-side hammer blow during mounting, because axial shock travels straight through the contact angle",
      "loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow",
      "pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed",
      "flaking that starts at the raceway shoulder on the thrust-loaded side when axial load repeatedly exceeds the design share",
      "current-erosion pitting on VFD-driven motor shafts, first visible as a grey frosted band across both raceways"
    ],
    "pitfalls": [
      "At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 300 mm bore bearing forgives nothing in a poorly machined housing.",
      "The 7900 extra-light section is chosen for speed and stiffness, not for load margin — check that C0 520 kN really covers the worst static case before substituting it for a 7000.",
      "If the application vibrates at standstill (transport, idle machine next to a running line), specify protection: the contact ellipse of a preloaded bearing false-brinells faster than a loose one.",
      "Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.",
      "Never use a four-point or double-row bearing as a like-for-like swap for a single 7960 without re-checking axial float, heat and housing width — the kinematics differ.",
      "The 360/520 kN ratings and 18.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7960; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 7960?",
        "a": "7960 is a single-row angular contact ball bearing to ISO 15: 300 mm bore, 420 mm outside diameter, 56 mm width (11.811 x 16.535 x 2.205 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 360 kN, C0 520 kN and a 18.2 kN fatigue load limit Pu; the grease limiting speed is 1,400 r/min and the oil rating 1,900 r/min; mass about 23700 g."
      },
      {
        "q": "How is the 7960 designation structured?",
        "a": "79 is the single-row dimension series (extra-light, high-speed 7900 single-row family); 60 encodes the 300 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 420 mm OD and 56 mm width follow the ISO 15 boundary-dimension plan for that series."
      },
      {
        "q": "Which axial direction does 7960 support?",
        "a": "One 7960 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact."
      },
      {
        "q": "What lubrication speeds does NTN print for 7960?",
        "a": "Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 1,400 r/min and the oil rating 1,900 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit."
      },
      {
        "q": "What should be checked before substituting another make for 7960?",
        "a": "The 300/420/56 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 360 kN / C0 520 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "7960",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=133",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "7960"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29412",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29412",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 60,
    "D_mm": 130,
    "B_mm": 42,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 315,
    "static_load_kN": 805,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 68.5,
    "limiting_speed_rpm": 2600,
    "max_rpm": 2600,
    "speed_oil_rpm": 2600,
    "weight_g": 2780,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 60 x 130 x 42 mm, NTN 29412 sits in the heavy-section 29400 spherical-thrust family of the spherical-thrust programme. Two fields make up the code — 294 is the dimension series (heavy-section 29400 spherical-thrust family) and 12 encodes the 60 mm bore (bore code x 5). A machined cage guided on the shaft-washer sleeve keeps the roller set spaced at the 2,600 r/min oil rating. Minimum axial load matters here too: at speed the rollers skid on a lightly loaded bearing, so check the catalogue minimum-load formula before downsizing the thrust spring. Check face runout of the support surfaces before assembly: the self-aligning feature absorbs steady misalignment, not a rocking seat. ",
    "applications": [
      "bulk-handler stacker/reclaimer slew pivots",
      "vertical hydro-turbine and large pump thrust supports",
      "rolling-mill screwdown and backup-roll thrust positions",
      "large crane and excavator slew thrust rings"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation"
    ],
    "pitfalls": [
      "Bearings of 60 mm bore need planned lifting and heating; a shaft washer driven on cold and crooked starts the failure clock before the first load.",
      "The 294 heavy section tops the plan at this bore with the largest 130 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "The C0a of 805 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.",
      "Shock thrust above C0a 805 kN leaves contact dents that seed fatigue; screwdown and press duties need the static check first.",
      "Oil is not optional at this rating: the 2,600 r/min figure assumes oil lubrication, and a grease conversion is a redesign, not a fill change.",
      "The Ca 315/C0a 805 kN ratings and 68.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29412; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29412?",
        "a": "29412 is a spherical roller thrust bearing to ISO 104: 60 mm shaft-washer bore, 130 mm outside diameter, 42 mm stack height (2.362 x 5.118 x 1.654 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 315 kN, C0a 805 kN and a 68.5 kN fatigue load limit Pu; limiting speed 2,600 r/min with oil lubrication; mass about 2780 g."
      },
      {
        "q": "How is the 29412 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 12 encodes the 60 mm bore (bore code x 5). The 130 mm OD and 42 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29412 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 2,600 r/min, for 29412?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29412?",
        "a": "The 60/130/42 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 315 kN / C0a 805 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29412-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×42 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29412"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29413",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29413",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 370,
    "static_load_kN": 945,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 75.5,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "speed_oil_rpm": 2400,
    "weight_g": 3440,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29413 is the 65 mm member of NTN's heavy-section 29400 spherical-thrust family: 140 mm over the housing washer, 45 mm tall. Decoding 29413: 294 is the dimension series (heavy-section 29400 spherical-thrust family), with 13 encodes the 65 mm bore (bore code x 5). Catalogue mass is about 3.4 kg for the full washer-and-roller stack. The 65/140/45 envelope follows ISO 104, so dimensional interchange holds between makers; osculation, roller profile and ratings do not automatically follow. Fill the housing with the specified oil to the level that reaches the cage — these bearings are oil-bath or circulation machines, not grease machines. ",
    "applications": [
      "rolling-mill screwdown and backup-roll thrust positions",
      "large crane and excavator slew thrust rings",
      "pellet-mill and grinder main-shaft thrust seats",
      "ship propulsion and rudder thrust blocks"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "fretting on the shaft seat after the washer crept under reversing axial shock",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces"
    ],
    "pitfalls": [
      "Bearings of 65 mm bore need planned lifting and heating; a shaft washer driven on cold and crooked starts the failure clock before the first load.",
      "The 294 heavy section tops the plan at this bore with the largest 140 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Mixing washers between bearings during overhaul is a real risk at this size — rollers and raceways run in together, so keep each 29413 stack as a set.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "The 45 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "The Ca 370/C0a 945 kN ratings and 75.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29413; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29413?",
        "a": "29413 is a spherical roller thrust bearing to ISO 104: 65 mm shaft-washer bore, 140 mm outside diameter, 45 mm stack height (2.559 x 5.512 x 1.772 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 370 kN, C0a 945 kN and a 75.5 kN fatigue load limit Pu; limiting speed 2,400 r/min with oil lubrication; mass about 3440 g."
      },
      {
        "q": "How is the 29413 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 13 encodes the 65 mm bore (bore code x 5). The 140 mm OD and 45 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29413 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 2,400 r/min, for 29413?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29413?",
        "a": "The 65/140/45 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 370 kN / C0a 945 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29413-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29413"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29414",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29414",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 70,
    "D_mm": 150,
    "B_mm": 48,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 405,
    "static_load_kN": 1040,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 87.5,
    "limiting_speed_rpm": 2200,
    "max_rpm": 2200,
    "speed_oil_rpm": 2200,
    "weight_g": 4190,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the heavy-section 29400 spherical-thrust family, 29414 measures 70 mm through the shaft washer, 150 mm over the outside and 48 mm in assembled height. NTN builds the number from 294 is the dimension series (heavy-section 29400 spherical-thrust family); 14 encodes the 70 mm bore (bore code x 5). With Ca 405 kN and C0a 1040 kN, each mm of bore carries about 5.79 kN of dynamic axial rating. Within the spherical-thrust plan, 292 is the light section and 294 the heavy one; stepping up from a 292 to a 294 at the same bore roughly doubles the C0a class. After filling with oil, rotate slowly and watch torque and temperature; a misrouted oil feed shows up in the first minutes of running. ",
    "applications": [
      "pellet-mill and grinder main-shaft thrust seats",
      "ship propulsion and rudder thrust blocks",
      "large mixer, reactor and agitator vertical shafts",
      "bulk-handler stacker/reclaimer slew pivots"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact"
    ],
    "pitfalls": [
      "Bearings of 70 mm bore need planned lifting and heating; a shaft washer driven on cold and crooked starts the failure clock before the first load.",
      "The 294 heavy section tops the plan at this bore with the largest 150 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "The 48 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "Self-aligning does not mean self-locating: the housing washer must stay free on its spherical seat — clamping it flat destroys the feature the 29414 was chosen for.",
      "The C0a of 1040 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.",
      "The Ca 405/C0a 1040 kN ratings and 87.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29414; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29414?",
        "a": "29414 is a spherical roller thrust bearing to ISO 104: 70 mm shaft-washer bore, 150 mm outside diameter, 48 mm stack height (2.756 x 5.906 x 1.89 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 405 kN, C0a 1040 kN and a 87.5 kN fatigue load limit Pu; limiting speed 2,200 r/min with oil lubrication; mass about 4190 g."
      },
      {
        "q": "How is the 29414 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 14 encodes the 70 mm bore (bore code x 5). The 150 mm OD and 48 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29414 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 2,200 r/min, for 29414?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29414?",
        "a": "The 70/150/48 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 405 kN / C0a 1040 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29414-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×150×48 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29414"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29415",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29415",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 75,
    "D_mm": 160,
    "B_mm": 51,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 465,
    "static_load_kN": 1190,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 102,
    "limiting_speed_rpm": 2100,
    "max_rpm": 2100,
    "speed_oil_rpm": 2100,
    "weight_g": 5070,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29415 is an NTN spherical roller thrust bearing of the heavy-section 29400 spherical-thrust family: 75 mm bore, 160 mm outside diameter, 51 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. The designation is 294 is the dimension series (heavy-section 29400 spherical-thrust family) plus 15 encodes the 75 mm bore (bore code x 5). Shaft and housing washers separate, so the 75 mm shaft washer can be mounted on the shaft before the roller set and housing washer follow. Against a thrust ball bearing of the same 75 mm bore, this bearing carries many times the load at lower speed — the trade is oil lubrication and price. On vertical shafts, confirm the minimum axial load from the rotor weight plus any spring preload before the first run at speed. ",
    "applications": [
      "large mixer, reactor and agitator vertical shafts",
      "bulk-handler stacker/reclaimer slew pivots",
      "vertical hydro-turbine and large pump thrust supports",
      "rolling-mill screwdown and backup-roll thrust positions"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 75 mm bore need planned lifting and heating; a shaft washer driven on cold and crooked starts the failure clock before the first load.",
      "The 294 heavy section tops the plan at this bore with the largest 160 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "Oil is not optional at this rating: the 2,100 r/min figure assumes oil lubrication, and a grease conversion is a redesign, not a fill change.",
      "Self-aligning does not mean self-locating: the housing washer must stay free on its spherical seat — clamping it flat destroys the feature the 29415 was chosen for.",
      "The Ca 465/C0a 1190 kN ratings and 102 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29415; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29415?",
        "a": "29415 is a spherical roller thrust bearing to ISO 104: 75 mm shaft-washer bore, 160 mm outside diameter, 51 mm stack height (2.953 x 6.299 x 2.008 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 465 kN, C0a 1190 kN and a 102 kN fatigue load limit Pu; limiting speed 2,100 r/min with oil lubrication; mass about 5070 g."
      },
      {
        "q": "How is the 29415 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 15 encodes the 75 mm bore (bore code x 5). The 160 mm OD and 51 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29415 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 2,100 r/min, for 29415?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29415?",
        "a": "The 75/160/51 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 465 kN / C0a 1190 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29415-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×160×51 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29415"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29416",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29416",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 80,
    "D_mm": 170,
    "B_mm": 54,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 510,
    "static_load_kN": 1380,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 102,
    "limiting_speed_rpm": 1900,
    "max_rpm": 1900,
    "speed_oil_rpm": 1900,
    "weight_g": 6090,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 29416 appears as a heavy-section 29400 spherical-thrust family bearing with a 80 mm shaft washer, 170 mm across the housing washer and 54 mm of height. Reading the code: 294 is the dimension series (heavy-section 29400 spherical-thrust family), and 16 encodes the 80 mm bore (bore code x 5). The single printed speed, 1,900 r/min, is an oil-lubrication figure: the catalogue greases these bearings only for the smallest duties, and this size is rated for oil. For oscillating or slow heavy duty, size from C0a 1380 kN with the static safety factor rather than from the life equation. Lift the bearing by the washers, never through the roller set; a 6.1 kg stack punishes improvisation. ",
    "applications": [
      "vertical hydro-turbine and large pump thrust supports",
      "rolling-mill screwdown and backup-roll thrust positions",
      "large crane and excavator slew thrust rings",
      "pellet-mill and grinder main-shaft thrust seats"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue",
      "fretting on the shaft seat after the washer crept under reversing axial shock"
    ],
    "pitfalls": [
      "Bearings of 80 mm bore need planned lifting and heating; a shaft washer driven on cold and crooked starts the failure clock before the first load.",
      "The 294 heavy section tops the plan at this bore with the largest 170 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Oil is not optional at this rating: the 1,900 r/min figure assumes oil lubrication, and a grease conversion is a redesign, not a fill change.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "Oil-bath level is set for the cage, not the housing: too low starves the contact, too high churns heat at the 1,900 r/min end of the range.",
      "The Ca 510/C0a 1380 kN ratings and 102 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29416; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29416?",
        "a": "29416 is a spherical roller thrust bearing to ISO 104: 80 mm shaft-washer bore, 170 mm outside diameter, 54 mm stack height (3.15 x 6.693 x 2.126 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 510 kN, C0a 1380 kN and a 102 kN fatigue load limit Pu; limiting speed 1,900 r/min with oil lubrication; mass about 6090 g."
      },
      {
        "q": "How is the 29416 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 16 encodes the 80 mm bore (bore code x 5). The 170 mm OD and 54 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29416 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,900 r/min, for 29416?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29416?",
        "a": "The 80/170/54 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 510 kN / C0a 1380 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29416-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×170×54 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29416"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29317",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29317",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 85,
    "D_mm": 150,
    "B_mm": 39,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 295,
    "static_load_kN": 820,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 78.5,
    "limiting_speed_rpm": 2300,
    "max_rpm": 2300,
    "speed_oil_rpm": 2300,
    "weight_g": 2940,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29317 is an NTN spherical roller thrust bearing of the medium-section 29300 spherical-thrust family: 85 mm bore, 150 mm outside diameter, 39 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. Decoding 29317: 293 is the dimension series (medium-section 29300 spherical-thrust family), with 17 encodes the 85 mm bore (bore code x 5). Asymmetric rollers and the angled contact mean the bearing also tolerates radial load — the catalogue allows a radial share while axial load clearly dominates. Within the spherical-thrust plan, 292 is the light section and 294 the heavy one; stepping up from a 292 to a 294 at the same bore roughly doubles the C0a class. Fill the housing with the specified oil to the level that reaches the cage — these bearings are oil-bath or circulation machines, not grease machines. ",
    "applications": [
      "ship propulsion and rudder thrust blocks",
      "large mixer, reactor and agitator vertical shafts",
      "bulk-handler stacker/reclaimer slew pivots",
      "vertical hydro-turbine and large pump thrust supports"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces"
    ],
    "pitfalls": [
      "Bearings of 85 mm bore need planned lifting and heating; a shaft washer driven on cold and crooked starts the failure clock before the first load.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 85 mm bore.",
      "The C0a of 820 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.",
      "Oil is not optional at this rating: the 2,300 r/min figure assumes oil lubrication, and a grease conversion is a redesign, not a fill change.",
      "Shock thrust above C0a 820 kN leaves contact dents that seed fatigue; screwdown and press duties need the static check first.",
      "The Ca 295/C0a 820 kN ratings and 78.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29317; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29317?",
        "a": "29317 is a spherical roller thrust bearing to ISO 104: 85 mm shaft-washer bore, 150 mm outside diameter, 39 mm stack height (3.346 x 5.906 x 1.535 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 295 kN, C0a 820 kN and a 78.5 kN fatigue load limit Pu; limiting speed 2,300 r/min with oil lubrication; mass about 2940 g."
      },
      {
        "q": "How is the 29317 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 17 encodes the 85 mm bore (bore code x 5). The 150 mm OD and 39 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29317 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 2,300 r/min, for 29317?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29317?",
        "a": "The 85/150/39 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 295 kN / C0a 820 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29317-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 85×150×39 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29317"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29417",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29417",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 85,
    "D_mm": 180,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 545,
    "static_load_kN": 1480,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 118,
    "limiting_speed_rpm": 1800,
    "max_rpm": 1800,
    "speed_oil_rpm": 1800,
    "weight_g": 7200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 29417 belongs to the heavy-section 29400 spherical-thrust family of spherical roller thrust bearings: 85 / 180 / 58 mm (bore / OD / height). Two fields make up the code — 294 is the dimension series (heavy-section 29400 spherical-thrust family) and 17 encodes the 85 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 545 kN against C0a 1480 kN — the roller contact line is why a 85 mm bore here out-carries any thrust ball bearing of the same size. If speed climbs toward the 1,800 r/min oil rating, the lubrication design — bath, circulation, cooling — becomes the real selection criterion. The 85 mm shaft washer normally mounts with a tight shaft fit; support the housing washer so it stays free to align on its spherical seat. ",
    "applications": [
      "large crane and excavator slew thrust rings",
      "pellet-mill and grinder main-shaft thrust seats",
      "ship propulsion and rudder thrust blocks",
      "large mixer, reactor and agitator vertical shafts"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation"
    ],
    "pitfalls": [
      "Bearings of 85 mm bore need planned lifting and heating; a shaft washer driven on cold and crooked starts the failure clock before the first load.",
      "The 294 heavy section tops the plan at this bore with the largest 180 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Below the minimum axial load the rollers skid; at 1,800 r/min the Ca of 545 kN never comes into play before the raceway is smeared.",
      "Below the minimum axial load the rollers skid; at 1,800 r/min the Ca of 545 kN never comes into play before the raceway is smeared.",
      "Below the minimum axial load the rollers skid; at 1,800 r/min the Ca of 545 kN never comes into play before the raceway is smeared.",
      "The Ca 545/C0a 1480 kN ratings and 118 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29417; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29417?",
        "a": "29417 is a spherical roller thrust bearing to ISO 104: 85 mm shaft-washer bore, 180 mm outside diameter, 58 mm stack height (3.346 x 7.087 x 2.283 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 545 kN, C0a 1480 kN and a 118 kN fatigue load limit Pu; limiting speed 1,800 r/min with oil lubrication; mass about 7200 g."
      },
      {
        "q": "How is the 29417 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 17 encodes the 85 mm bore (bore code x 5). The 180 mm OD and 58 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29417 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,800 r/min, for 29417?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29417?",
        "a": "The 85/180/58 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 545 kN / C0a 1480 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29417-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 85×180×58 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29417"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29318",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29318",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 90,
    "D_mm": 155,
    "B_mm": 39,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 320,
    "static_load_kN": 915,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 84,
    "limiting_speed_rpm": 2300,
    "max_rpm": 2300,
    "speed_oil_rpm": 2300,
    "weight_g": 3080,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 29318 appears as a medium-section 29300 spherical-thrust family bearing with a 90 mm shaft washer, 155 mm across the housing washer and 39 mm of height. NTN builds the number from 293 is the dimension series (medium-section 29300 spherical-thrust family); 18 encodes the 90 mm bore (bore code x 5). The spherical housing raceway lets the shaft washer align itself as the seats settle — the property that keeps the 915 kN static rating honest in real housings. Against a thrust ball bearing of the same 90 mm bore, this bearing carries many times the load at lower speed — the trade is oil lubrication and price. After filling with oil, rotate slowly and watch torque and temperature; a misrouted oil feed shows up in the first minutes of running. ",
    "applications": [
      "bulk-handler stacker/reclaimer slew pivots",
      "vertical hydro-turbine and large pump thrust supports",
      "rolling-mill screwdown and backup-roll thrust positions",
      "large crane and excavator slew thrust rings"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact"
    ],
    "pitfalls": [
      "Bearings of 90 mm bore need planned lifting and heating; a shaft washer driven on cold and crooked starts the failure clock before the first load.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 90 mm bore.",
      "Mixing washers between bearings during overhaul is a real risk at this size — rollers and raceways run in together, so keep each 29318 stack as a set.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "Do not let the self-aligning travel absorb a bent shaft: the bearing aligns to seats, not to a shaft that whips.",
      "The Ca 320/C0a 915 kN ratings and 84 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29318; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29318?",
        "a": "29318 is a spherical roller thrust bearing to ISO 104: 90 mm shaft-washer bore, 155 mm outside diameter, 39 mm stack height (3.543 x 6.102 x 1.535 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 320 kN, C0a 915 kN and a 84 kN fatigue load limit Pu; limiting speed 2,300 r/min with oil lubrication; mass about 3080 g."
      },
      {
        "q": "How is the 29318 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 18 encodes the 90 mm bore (bore code x 5). The 155 mm OD and 39 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29318 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 2,300 r/min, for 29318?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29318?",
        "a": "The 90/155/39 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 320 kN / C0a 915 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29318-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×155×39 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29318"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29418",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29418",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 90,
    "D_mm": 190,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 610,
    "static_load_kN": 1680,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 121,
    "limiting_speed_rpm": 1700,
    "max_rpm": 1700,
    "speed_oil_rpm": 1700,
    "weight_g": 8380,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The heavy-section 29400 spherical-thrust family entry 29418 combines a spherical housing-washer raceway with asymmetric barrel rollers in 60 mm of stack height. Decoding 29418: 294 is the dimension series (heavy-section 29400 spherical-thrust family), with 18 encodes the 90 mm bore (bore code x 5). The static/dynamic ratio of 2.75 tells the story of a roller raceway: enormous reserve for slow, shocked or oscillating thrust. Where the shaft also needs radial location, pair this bearing with a spherical roller or cylindrical radial bearing — the thrust bearing is not a radial guide. Torque the shaft nut against the shaft washer shoulder and verify axial clamping — a loose shaft washer frets the seat under 610 kN class thrust. ",
    "applications": [
      "ship propulsion and rudder thrust blocks",
      "large mixer, reactor and agitator vertical shafts",
      "bulk-handler stacker/reclaimer slew pivots",
      "vertical hydro-turbine and large pump thrust supports"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "fretting on the shaft seat after the washer crept under reversing axial shock",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces"
    ],
    "pitfalls": [
      "Bearings of 90 mm bore need planned lifting and heating; a shaft washer driven on cold and crooked starts the failure clock before the first load.",
      "The 294 heavy section tops the plan at this bore with the largest 190 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Do not let the self-aligning travel absorb a bent shaft: the bearing aligns to seats, not to a shaft that whips.",
      "The C0a of 1680 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "The Ca 610/C0a 1680 kN ratings and 121 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29418; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29418?",
        "a": "29418 is a spherical roller thrust bearing to ISO 104: 90 mm shaft-washer bore, 190 mm outside diameter, 60 mm stack height (3.543 x 7.48 x 2.362 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 610 kN, C0a 1680 kN and a 121 kN fatigue load limit Pu; limiting speed 1,700 r/min with oil lubrication; mass about 8380 g."
      },
      {
        "q": "How is the 29418 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 18 encodes the 90 mm bore (bore code x 5). The 190 mm OD and 60 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29418 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,700 r/min, for 29418?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29418?",
        "a": "The 90/190/60 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 610 kN / C0a 1680 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29418-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×190×60 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29418"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29320",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29320",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 100,
    "D_mm": 170,
    "B_mm": 42,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 385,
    "static_load_kN": 1160,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 96,
    "limiting_speed_rpm": 2100,
    "max_rpm": 2100,
    "speed_oil_rpm": 2100,
    "weight_g": 3940,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The medium-section 29300 spherical-thrust family entry 29320 combines a spherical housing-washer raceway with asymmetric barrel rollers in 42 mm of stack height. Decoding 29320: 293 is the dimension series (medium-section 29300 spherical-thrust family), with 20 encodes the 100 mm bore (bore code x 5). The single printed speed, 2,100 r/min, is an oil-lubrication figure: the catalogue greases these bearings only for the smallest duties, and this size is rated for oil. Choose the medium-section 29300 spherical-thrust family when heavy thrust meets misalignment: vertical turbines, mills and slew pivots are the classic homes. Check face runout of the support surfaces before assembly: the self-aligning feature absorbs steady misalignment, not a rocking seat. ",
    "applications": [
      "large mixer, reactor and agitator vertical shafts",
      "bulk-handler stacker/reclaimer slew pivots",
      "vertical hydro-turbine and large pump thrust supports",
      "rolling-mill screwdown and backup-roll thrust positions"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "fretting on the shaft seat after the washer crept under reversing axial shock",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces"
    ],
    "pitfalls": [
      "Bearings of 100 mm bore need planned lifting and heating; a shaft washer driven on cold and crooked starts the failure clock before the first load.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 100 mm bore.",
      "Shock thrust above C0a 1160 kN leaves contact dents that seed fatigue; screwdown and press duties need the static check first.",
      "The C0a of 1160 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.",
      "Oil-bath level is set for the cage, not the housing: too low starves the contact, too high churns heat at the 2,100 r/min end of the range.",
      "The Ca 385/C0a 1160 kN ratings and 96 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29320; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29320?",
        "a": "29320 is a spherical roller thrust bearing to ISO 104: 100 mm shaft-washer bore, 170 mm outside diameter, 42 mm stack height (3.937 x 6.693 x 1.654 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 385 kN, C0a 1160 kN and a 96 kN fatigue load limit Pu; limiting speed 2,100 r/min with oil lubrication; mass about 3940 g."
      },
      {
        "q": "How is the 29320 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 20 encodes the 100 mm bore (bore code x 5). The 170 mm OD and 42 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29320 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 2,100 r/min, for 29320?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29320?",
        "a": "The 100/170/42 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 385 kN / C0a 1160 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29320-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 100×170×42 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29320"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29420",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29420",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 100,
    "D_mm": 210,
    "B_mm": 67,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 760,
    "static_load_kN": 2130,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 156,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 1500,
    "weight_g": 11500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29420 is the 100 mm member of NTN's heavy-section 29400 spherical-thrust family: 210 mm over the housing washer, 67 mm tall. Two fields make up the code — 294 is the dimension series (heavy-section 29400 spherical-thrust family) and 20 encodes the 100 mm bore (bore code x 5). A machined cage guided on the shaft-washer sleeve keeps the roller set spaced at the 1,500 r/min oil rating. Within the spherical-thrust plan, 292 is the light section and 294 the heavy one; stepping up from a 292 to a 294 at the same bore roughly doubles the C0a class. Lift the bearing by the washers, never through the roller set; a 12 kg stack punishes improvisation. ",
    "applications": [
      "pellet-mill and grinder main-shaft thrust seats",
      "ship propulsion and rudder thrust blocks",
      "large mixer, reactor and agitator vertical shafts",
      "bulk-handler stacker/reclaimer slew pivots"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation"
    ],
    "pitfalls": [
      "Bearings of 100 mm bore need planned lifting and heating; a shaft washer driven on cold and crooked starts the failure clock before the first load.",
      "The 294 heavy section tops the plan at this bore with the largest 210 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "The 67 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "Mixing washers between bearings during overhaul is a real risk at this size — rollers and raceways run in together, so keep each 29420 stack as a set.",
      "Oil is not optional at this rating: the 1,500 r/min figure assumes oil lubrication, and a grease conversion is a redesign, not a fill change.",
      "The Ca 760/C0a 2130 kN ratings and 156 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29420; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29420?",
        "a": "29420 is a spherical roller thrust bearing to ISO 104: 100 mm shaft-washer bore, 210 mm outside diameter, 67 mm stack height (3.937 x 8.268 x 2.638 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 760 kN, C0a 2130 kN and a 156 kN fatigue load limit Pu; limiting speed 1,500 r/min with oil lubrication; mass about 11500 g."
      },
      {
        "q": "How is the 29420 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 20 encodes the 100 mm bore (bore code x 5). The 210 mm OD and 67 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29420 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,500 r/min, for 29420?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29420?",
        "a": "The 100/210/67 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 760 kN / C0a 2130 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29420-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 100×210×67 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29420"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29322",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29322",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 110,
    "D_mm": 190,
    "B_mm": 48,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 495,
    "static_load_kN": 1500,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 120,
    "limiting_speed_rpm": 1800,
    "max_rpm": 1800,
    "speed_oil_rpm": 1800,
    "weight_g": 5780,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29322 is the 110 mm member of NTN's medium-section 29300 spherical-thrust family: 190 mm over the housing washer, 48 mm tall. The designation is 293 is the dimension series (medium-section 29300 spherical-thrust family) plus 22 encodes the 110 mm bore (bore code x 5). The static/dynamic ratio of 3.03 tells the story of a roller raceway: enormous reserve for slow, shocked or oscillating thrust. The 110/190/48 envelope follows ISO 104, so dimensional interchange holds between makers; osculation, roller profile and ratings do not automatically follow. After filling with oil, rotate slowly and watch torque and temperature; a misrouted oil feed shows up in the first minutes of running. ",
    "applications": [
      "large crane and excavator slew thrust rings",
      "pellet-mill and grinder main-shaft thrust seats",
      "ship propulsion and rudder thrust blocks",
      "large mixer, reactor and agitator vertical shafts"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue"
    ],
    "pitfalls": [
      "Bearings of 110 mm bore need planned lifting and heating; a shaft washer driven on cold and crooked starts the failure clock before the first load.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 110 mm bore.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "Mixing washers between bearings during overhaul is a real risk at this size — rollers and raceways run in together, so keep each 29322 stack as a set.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "The Ca 495/C0a 1500 kN ratings and 120 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29322; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29322?",
        "a": "29322 is a spherical roller thrust bearing to ISO 104: 110 mm shaft-washer bore, 190 mm outside diameter, 48 mm stack height (4.331 x 7.48 x 1.89 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 495 kN, C0a 1500 kN and a 120 kN fatigue load limit Pu; limiting speed 1,800 r/min with oil lubrication; mass about 5780 g."
      },
      {
        "q": "How is the 29322 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 22 encodes the 110 mm bore (bore code x 5). The 190 mm OD and 48 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29322 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,800 r/min, for 29322?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29322?",
        "a": "The 110/190/48 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 495 kN / C0a 1500 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29322-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×190×48 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29322"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29422",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29422",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 110,
    "D_mm": 230,
    "B_mm": 73,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 940,
    "static_load_kN": 2620,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 193,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1400,
    "weight_g": 15000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29422 is an NTN spherical roller thrust bearing of the heavy-section 29400 spherical-thrust family: 110 mm bore, 230 mm outside diameter, 73 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. NTN builds the number from 294 is the dimension series (heavy-section 29400 spherical-thrust family); 22 encodes the 110 mm bore (bore code x 5). With Ca 940 kN and C0a 2620 kN, each mm of bore carries about 8.55 kN of dynamic axial rating. For oscillating or slow heavy duty, size from C0a 2620 kN with the static safety factor rather than from the life equation. Torque the shaft nut against the shaft washer shoulder and verify axial clamping — a loose shaft washer frets the seat under 940 kN class thrust. ",
    "applications": [
      "vertical hydro-turbine and large pump thrust supports",
      "rolling-mill screwdown and backup-roll thrust positions",
      "large crane and excavator slew thrust rings",
      "pellet-mill and grinder main-shaft thrust seats"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact"
    ],
    "pitfalls": [
      "Bearings of 110 mm bore need planned lifting and heating; a shaft washer driven on cold and crooked starts the failure clock before the first load.",
      "The 294 heavy section tops the plan at this bore with the largest 230 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Oil is not optional at this rating: the 1,400 r/min figure assumes oil lubrication, and a grease conversion is a redesign, not a fill change.",
      "The 73 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "The C0a of 2620 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.",
      "The Ca 940/C0a 2620 kN ratings and 193 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29422; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29422?",
        "a": "29422 is a spherical roller thrust bearing to ISO 104: 110 mm shaft-washer bore, 230 mm outside diameter, 73 mm stack height (4.331 x 9.055 x 2.874 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 940 kN, C0a 2620 kN and a 193 kN fatigue load limit Pu; limiting speed 1,400 r/min with oil lubrication; mass about 15000 g."
      },
      {
        "q": "How is the 29422 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 22 encodes the 110 mm bore (bore code x 5). The 230 mm OD and 73 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29422 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,400 r/min, for 29422?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29422?",
        "a": "The 110/230/73 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 940 kN / C0a 2620 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29422-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×230×73 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29422"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29324",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29324",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 120,
    "D_mm": 210,
    "B_mm": 54,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 595,
    "static_load_kN": 1770,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 151,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 1600,
    "weight_g": 7920,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29324 is an NTN spherical roller thrust bearing of the medium-section 29300 spherical-thrust family: 120 mm bore, 210 mm outside diameter, 54 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. Two fields make up the code — 293 is the dimension series (medium-section 29300 spherical-thrust family) and 24 encodes the 120 mm bore (bore code x 5). At 54 mm of height the bearing packs the medium-section capacity into a stack far shorter than a comparable multi-row ball arrangement. Against a thrust ball bearing of the same 120 mm bore, this bearing carries many times the load at lower speed — the trade is oil lubrication and price. Lift the bearing by the washers, never through the roller set; a 7.9 kg stack punishes improvisation. ",
    "applications": [
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation"
    ],
    "pitfalls": [
      "At 120 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 120 mm bore.",
      "Mixing washers between bearings during overhaul is a real risk at this size — rollers and raceways run in together, so keep each 29324 stack as a set.",
      "The 54 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "The Ca 595/C0a 1770 kN ratings and 151 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29324; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29324?",
        "a": "29324 is a spherical roller thrust bearing to ISO 104: 120 mm shaft-washer bore, 210 mm outside diameter, 54 mm stack height (4.724 x 8.268 x 2.126 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 595 kN, C0a 1770 kN and a 151 kN fatigue load limit Pu; limiting speed 1,600 r/min with oil lubrication; mass about 7920 g."
      },
      {
        "q": "How is the 29324 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 24 encodes the 120 mm bore (bore code x 5). The 210 mm OD and 54 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29324 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,600 r/min, for 29324?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29324?",
        "a": "The 120/210/54 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 595 kN / C0a 1770 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29324-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×210×54 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29324"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29424",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29424",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 120,
    "D_mm": 250,
    "B_mm": 78,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 1080,
    "static_load_kN": 3050,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 212,
    "limiting_speed_rpm": 1300,
    "max_rpm": 1300,
    "speed_oil_rpm": 1300,
    "weight_g": 18600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 29424 belongs to the heavy-section 29400 spherical-thrust family of spherical roller thrust bearings: 120 / 250 / 78 mm (bore / OD / height). Reading the code: 294 is the dimension series (heavy-section 29400 spherical-thrust family), and 24 encodes the 120 mm bore (bore code x 5). The single printed speed, 1,300 r/min, is an oil-lubrication figure: the catalogue greases these bearings only for the smallest duties, and this size is rated for oil. Where the shaft also needs radial location, pair this bearing with a spherical roller or cylindrical radial bearing — the thrust bearing is not a radial guide. Fill the housing with the specified oil to the level that reaches the cage — these bearings are oil-bath or circulation machines, not grease machines. ",
    "applications": [
      "rotary kiln and furnace thrust positions",
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "fretting on the shaft seat after the washer crept under reversing axial shock",
      "fretting on the shaft seat after the washer crept under reversing axial shock"
    ],
    "pitfalls": [
      "At 120 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 294 heavy section tops the plan at this bore with the largest 250 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Do not let the self-aligning travel absorb a bent shaft: the bearing aligns to seats, not to a shaft that whips.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "Oil-bath level is set for the cage, not the housing: too low starves the contact, too high churns heat at the 1,300 r/min end of the range.",
      "The Ca 1080/C0a 3050 kN ratings and 212 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29424; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29424?",
        "a": "29424 is a spherical roller thrust bearing to ISO 104: 120 mm shaft-washer bore, 250 mm outside diameter, 78 mm stack height (4.724 x 9.843 x 3.071 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1080 kN, C0a 3050 kN and a 212 kN fatigue load limit Pu; limiting speed 1,300 r/min with oil lubrication; mass about 18600 g."
      },
      {
        "q": "How is the 29424 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 24 encodes the 120 mm bore (bore code x 5). The 250 mm OD and 78 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29424 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,300 r/min, for 29424?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29424?",
        "a": "The 120/250/78 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1080 kN / C0a 3050 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29424-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×250×78 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29424"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29326",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29326",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 130,
    "D_mm": 225,
    "B_mm": 58,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 685,
    "static_load_kN": 2100,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 168,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 1500,
    "weight_g": 9760,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 29326 belongs to the medium-section 29300 spherical-thrust family of spherical roller thrust bearings: 130 / 225 / 58 mm (bore / OD / height). NTN builds the number from 293 is the dimension series (medium-section 29300 spherical-thrust family); 26 encodes the 130 mm bore (bore code x 5). The spherical housing raceway lets the shaft washer align itself as the seats settle — the property that keeps the 2100 kN static rating honest in real housings. If speed climbs toward the 1,500 r/min oil rating, the lubrication design — bath, circulation, cooling — becomes the real selection criterion. Torque the shaft nut against the shaft washer shoulder and verify axial clamping — a loose shaft washer frets the seat under 685 kN class thrust. ",
    "applications": [
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions",
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact"
    ],
    "pitfalls": [
      "At 130 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 130 mm bore.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "Do not let the self-aligning travel absorb a bent shaft: the bearing aligns to seats, not to a shaft that whips.",
      "The Ca 685/C0a 2100 kN ratings and 168 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29326; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29326?",
        "a": "29326 is a spherical roller thrust bearing to ISO 104: 130 mm shaft-washer bore, 225 mm outside diameter, 58 mm stack height (5.118 x 8.858 x 2.283 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 685 kN, C0a 2100 kN and a 168 kN fatigue load limit Pu; limiting speed 1,500 r/min with oil lubrication; mass about 9760 g."
      },
      {
        "q": "How is the 29326 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 26 encodes the 130 mm bore (bore code x 5). The 225 mm OD and 58 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29326 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,500 r/min, for 29326?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29326?",
        "a": "The 130/225/58 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 685 kN / C0a 2100 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29326-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×225×58 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29326"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29426",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29426",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 130,
    "D_mm": 270,
    "B_mm": 85,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 1200,
    "static_load_kN": 3550,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 232,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1200,
    "weight_g": 23700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 130 x 270 x 85 mm, NTN 29426 sits in the heavy-section 29400 spherical-thrust family of the spherical-thrust programme. Decoding 29426: 294 is the dimension series (heavy-section 29400 spherical-thrust family), with 26 encodes the 130 mm bore (bore code x 5). The static/dynamic ratio of 2.96 tells the story of a roller raceway: enormous reserve for slow, shocked or oscillating thrust. Choose the heavy-section 29400 spherical-thrust family when heavy thrust meets misalignment: vertical turbines, mills and slew pivots are the classic homes. On vertical shafts, confirm the minimum axial load from the rotor weight plus any spring preload before the first run at speed. ",
    "applications": [
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces"
    ],
    "pitfalls": [
      "At 130 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 294 heavy section tops the plan at this bore with the largest 270 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Shock thrust above C0a 3550 kN leaves contact dents that seed fatigue; screwdown and press duties need the static check first.",
      "Oil is not optional at this rating: the 1,200 r/min figure assumes oil lubrication, and a grease conversion is a redesign, not a fill change.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "The Ca 1200/C0a 3550 kN ratings and 232 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29426; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29426?",
        "a": "29426 is a spherical roller thrust bearing to ISO 104: 130 mm shaft-washer bore, 270 mm outside diameter, 85 mm stack height (5.118 x 10.63 x 3.346 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1200 kN, C0a 3550 kN and a 232 kN fatigue load limit Pu; limiting speed 1,200 r/min with oil lubrication; mass about 23700 g."
      },
      {
        "q": "How is the 29426 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 26 encodes the 130 mm bore (bore code x 5). The 270 mm OD and 85 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29426 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,200 r/min, for 29426?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29426?",
        "a": "The 130/270/85 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1200 kN / C0a 3550 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29426-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×270×85 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29426"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29328",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29328",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 140,
    "D_mm": 240,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 760,
    "static_load_kN": 2360,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 182,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1400,
    "weight_g": 11400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 140 x 240 x 60 mm, NTN 29328 sits in the medium-section 29300 spherical-thrust family of the spherical-thrust programme. Reading the code: 293 is the dimension series (medium-section 29300 spherical-thrust family), and 28 encodes the 140 mm bore (bore code x 5). Catalogue mass is about 11 kg for the full washer-and-roller stack. Selection starts from the load case: axial must dominate, and any radial share must stay within the catalogue combined-load rule while the bearing self-aligns. Fill the housing with the specified oil to the level that reaches the cage — these bearings are oil-bath or circulation machines, not grease machines. ",
    "applications": [
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue",
      "fretting on the shaft seat after the washer crept under reversing axial shock"
    ],
    "pitfalls": [
      "At 140 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 140 mm bore.",
      "Below the minimum axial load the rollers skid; at 1,400 r/min the Ca of 760 kN never comes into play before the raceway is smeared.",
      "Oil is not optional at this rating: the 1,400 r/min figure assumes oil lubrication, and a grease conversion is a redesign, not a fill change.",
      "The 60 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "The Ca 760/C0a 2360 kN ratings and 182 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29328; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29328?",
        "a": "29328 is a spherical roller thrust bearing to ISO 104: 140 mm shaft-washer bore, 240 mm outside diameter, 60 mm stack height (5.512 x 9.449 x 2.362 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 760 kN, C0a 2360 kN and a 182 kN fatigue load limit Pu; limiting speed 1,400 r/min with oil lubrication; mass about 11400 g."
      },
      {
        "q": "How is the 29328 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 28 encodes the 140 mm bore (bore code x 5). The 240 mm OD and 60 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29328 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,400 r/min, for 29328?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29328?",
        "a": "The 140/240/60 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 760 kN / C0a 2360 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29328-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×240×60 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29328"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29428",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29428",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 140,
    "D_mm": 280,
    "B_mm": 85,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 1240,
    "static_load_kN": 3750,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 252,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1200,
    "weight_g": 25200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the heavy-section 29400 spherical-thrust family, 29428 measures 140 mm through the shaft washer, 280 mm over the outside and 85 mm in assembled height. The designation is 294 is the dimension series (heavy-section 29400 spherical-thrust family) plus 28 encodes the 140 mm bore (bore code x 5). At 85 mm of height the bearing packs the heavy-section capacity into a stack far shorter than a comparable multi-row ball arrangement. The 140/280/85 envelope follows ISO 104, so dimensional interchange holds between makers; osculation, roller profile and ratings do not automatically follow. The 140 mm shaft washer normally mounts with a tight shaft fit; support the housing washer so it stays free to align on its spherical seat. ",
    "applications": [
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue"
    ],
    "pitfalls": [
      "At 140 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 294 heavy section tops the plan at this bore with the largest 280 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "Below the minimum axial load the rollers skid; at 1,200 r/min the Ca of 1240 kN never comes into play before the raceway is smeared.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "The Ca 1240/C0a 3750 kN ratings and 252 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29428; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29428?",
        "a": "29428 is a spherical roller thrust bearing to ISO 104: 140 mm shaft-washer bore, 280 mm outside diameter, 85 mm stack height (5.512 x 11.024 x 3.346 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1240 kN, C0a 3750 kN and a 252 kN fatigue load limit Pu; limiting speed 1,200 r/min with oil lubrication; mass about 25200 g."
      },
      {
        "q": "How is the 29428 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 28 encodes the 140 mm bore (bore code x 5). The 280 mm OD and 85 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29428 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,200 r/min, for 29428?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29428?",
        "a": "The 140/280/85 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1240 kN / C0a 3750 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29428-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×280×85 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29428"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29230",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29230",
    "series": "29200-series",
    "type": "spherical_roller_thrust",
    "d_mm": 150,
    "D_mm": 215,
    "B_mm": 39,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 380,
    "static_load_kN": 1340,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 122,
    "limiting_speed_rpm": 1800,
    "max_rpm": 1800,
    "speed_oil_rpm": 1800,
    "weight_g": 4560,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 150 x 215 x 39 mm, NTN 29230 sits in the light-section 29200 spherical-thrust family of the spherical-thrust programme. Reading the code: 292 is the dimension series (light-section 29200 spherical-thrust family), and 30 encodes the 150 mm bore (bore code x 5). Shaft and housing washers separate, so the 150 mm shaft washer can be mounted on the shaft before the roller set and housing washer follow. If speed climbs toward the 1,800 r/min oil rating, the lubrication design — bath, circulation, cooling — becomes the real selection criterion. Torque the shaft nut against the shaft washer shoulder and verify axial clamping — a loose shaft washer frets the seat under 380 kN class thrust. ",
    "applications": [
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact",
      "fretting on the shaft seat after the washer crept under reversing axial shock"
    ],
    "pitfalls": [
      "At 150 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 292 light section is the speed-and-space end of the spherical-thrust plan — for the same 150 mm bore it trades capacity for a smaller 215 mm OD and lower height.",
      "Oil-bath level is set for the cage, not the housing: too low starves the contact, too high churns heat at the 1,800 r/min end of the range.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "Self-aligning does not mean self-locating: the housing washer must stay free on its spherical seat — clamping it flat destroys the feature the 29230 was chosen for.",
      "The Ca 380/C0a 1340 kN ratings and 122 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29230; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29230?",
        "a": "29230 is a spherical roller thrust bearing to ISO 104: 150 mm shaft-washer bore, 215 mm outside diameter, 39 mm stack height (5.906 x 8.465 x 1.535 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 380 kN, C0a 1340 kN and a 122 kN fatigue load limit Pu; limiting speed 1,800 r/min with oil lubrication; mass about 4560 g."
      },
      {
        "q": "How is the 29230 designation structured?",
        "a": "292 is the dimension series (light-section 29200 spherical-thrust family); 30 encodes the 150 mm bore (bore code x 5). The 215 mm OD and 39 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29230 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,800 r/min, for 29230?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29230?",
        "a": "The 150/215/39 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 380 kN / C0a 1340 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29230-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×215×39 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29230"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29330",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29330",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 150,
    "D_mm": 250,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 750,
    "static_load_kN": 2390,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 191,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1400,
    "weight_g": 12000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the medium-section 29300 spherical-thrust family, 29330 measures 150 mm through the shaft washer, 250 mm over the outside and 60 mm in assembled height. The designation is 293 is the dimension series (medium-section 29300 spherical-thrust family) plus 30 encodes the 150 mm bore (bore code x 5). The static/dynamic ratio of 3.19 tells the story of a roller raceway: enormous reserve for slow, shocked or oscillating thrust. Against a thrust ball bearing of the same 150 mm bore, this bearing carries many times the load at lower speed — the trade is oil lubrication and price. Torque the shaft nut against the shaft washer shoulder and verify axial clamping — a loose shaft washer frets the seat under 750 kN class thrust. ",
    "applications": [
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue"
    ],
    "pitfalls": [
      "At 150 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 150 mm bore.",
      "Mixing washers between bearings during overhaul is a real risk at this size — rollers and raceways run in together, so keep each 29330 stack as a set.",
      "Below the minimum axial load the rollers skid; at 1,400 r/min the Ca of 750 kN never comes into play before the raceway is smeared.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "The Ca 750/C0a 2390 kN ratings and 191 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29330; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29330?",
        "a": "29330 is a spherical roller thrust bearing to ISO 104: 150 mm shaft-washer bore, 250 mm outside diameter, 60 mm stack height (5.906 x 9.843 x 2.362 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 750 kN, C0a 2390 kN and a 191 kN fatigue load limit Pu; limiting speed 1,400 r/min with oil lubrication; mass about 12000 g."
      },
      {
        "q": "How is the 29330 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 30 encodes the 150 mm bore (bore code x 5). The 250 mm OD and 60 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29330 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,400 r/min, for 29330?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29330?",
        "a": "The 150/250/60 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 750 kN / C0a 2390 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29330-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×250×60 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29330"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29430",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29430",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 150,
    "D_mm": 300,
    "B_mm": 90,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 1430,
    "static_load_kN": 4350,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 280,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1100,
    "weight_g": 30500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 29430 appears as a heavy-section 29400 spherical-thrust family bearing with a 150 mm shaft washer, 300 mm across the housing washer and 90 mm of height. NTN builds the number from 294 is the dimension series (heavy-section 29400 spherical-thrust family); 30 encodes the 150 mm bore (bore code x 5). With Ca 1430 kN and C0a 4350 kN, each mm of bore carries about 9.53 kN of dynamic axial rating. Where the shaft also needs radial location, pair this bearing with a spherical roller or cylindrical radial bearing — the thrust bearing is not a radial guide. On vertical shafts, confirm the minimum axial load from the rotor weight plus any spring preload before the first run at speed. ",
    "applications": [
      "rotary kiln and furnace thrust positions",
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "fretting on the shaft seat after the washer crept under reversing axial shock",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact"
    ],
    "pitfalls": [
      "At 150 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 294 heavy section tops the plan at this bore with the largest 300 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Do not let the self-aligning travel absorb a bent shaft: the bearing aligns to seats, not to a shaft that whips.",
      "Do not let the self-aligning travel absorb a bent shaft: the bearing aligns to seats, not to a shaft that whips.",
      "The C0a of 4350 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.",
      "The Ca 1430/C0a 4350 kN ratings and 280 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29430; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29430?",
        "a": "29430 is a spherical roller thrust bearing to ISO 104: 150 mm shaft-washer bore, 300 mm outside diameter, 90 mm stack height (5.906 x 11.811 x 3.543 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1430 kN, C0a 4350 kN and a 280 kN fatigue load limit Pu; limiting speed 1,100 r/min with oil lubrication; mass about 30500 g."
      },
      {
        "q": "How is the 29430 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 30 encodes the 150 mm bore (bore code x 5). The 300 mm OD and 90 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29430 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,100 r/min, for 29430?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29430?",
        "a": "The 150/300/90 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1430 kN / C0a 4350 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29430-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×300×90 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29430"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29232",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29232",
    "series": "29200-series",
    "type": "spherical_roller_thrust",
    "d_mm": 160,
    "D_mm": 225,
    "B_mm": 39,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 400,
    "static_load_kN": 1460,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 126,
    "limiting_speed_rpm": 1700,
    "max_rpm": 1700,
    "speed_oil_rpm": 1700,
    "weight_g": 4880,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the light-section 29200 spherical-thrust family, 29232 measures 160 mm through the shaft washer, 225 mm over the outside and 39 mm in assembled height. Decoding 29232: 292 is the dimension series (light-section 29200 spherical-thrust family), with 32 encodes the 160 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 400 kN against C0a 1460 kN — the roller contact line is why a 160 mm bore here out-carries any thrust ball bearing of the same size. Selection starts from the load case: axial must dominate, and any radial share must stay within the catalogue combined-load rule while the bearing self-aligns. Fill the housing with the specified oil to the level that reaches the cage — these bearings are oil-bath or circulation machines, not grease machines. ",
    "applications": [
      "rotary kiln and furnace thrust positions",
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces"
    ],
    "pitfalls": [
      "At 160 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 292 light section is the speed-and-space end of the spherical-thrust plan — for the same 160 mm bore it trades capacity for a smaller 225 mm OD and lower height.",
      "Self-aligning does not mean self-locating: the housing washer must stay free on its spherical seat — clamping it flat destroys the feature the 29232 was chosen for.",
      "The C0a of 1460 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.",
      "Below the minimum axial load the rollers skid; at 1,700 r/min the Ca of 400 kN never comes into play before the raceway is smeared.",
      "The Ca 400/C0a 1460 kN ratings and 126 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29232; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29232?",
        "a": "29232 is a spherical roller thrust bearing to ISO 104: 160 mm shaft-washer bore, 225 mm outside diameter, 39 mm stack height (6.299 x 8.858 x 1.535 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 400 kN, C0a 1460 kN and a 126 kN fatigue load limit Pu; limiting speed 1,700 r/min with oil lubrication; mass about 4880 g."
      },
      {
        "q": "How is the 29232 designation structured?",
        "a": "292 is the dimension series (light-section 29200 spherical-thrust family); 32 encodes the 160 mm bore (bore code x 5). The 225 mm OD and 39 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29232 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,700 r/min, for 29232?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29232?",
        "a": "The 160/225/39 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 400 kN / C0a 1460 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29232",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29232"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29332",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29332",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 160,
    "D_mm": 270,
    "B_mm": 67,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 915,
    "static_load_kN": 2860,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 223,
    "limiting_speed_rpm": 1300,
    "max_rpm": 1300,
    "speed_oil_rpm": 1300,
    "weight_g": 15900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 29332 appears as a medium-section 29300 spherical-thrust family bearing with a 160 mm shaft washer, 270 mm across the housing washer and 67 mm of height. Two fields make up the code — 293 is the dimension series (medium-section 29300 spherical-thrust family) and 32 encodes the 160 mm bore (bore code x 5). At 67 mm of height the bearing packs the medium-section capacity into a stack far shorter than a comparable multi-row ball arrangement. If speed climbs toward the 1,300 r/min oil rating, the lubrication design — bath, circulation, cooling — becomes the real selection criterion. Fill the housing with the specified oil to the level that reaches the cage — these bearings are oil-bath or circulation machines, not grease machines. ",
    "applications": [
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions",
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation"
    ],
    "pitfalls": [
      "At 160 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 160 mm bore.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "Do not let the self-aligning travel absorb a bent shaft: the bearing aligns to seats, not to a shaft that whips.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "The Ca 915/C0a 2860 kN ratings and 223 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29332; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29332?",
        "a": "29332 is a spherical roller thrust bearing to ISO 104: 160 mm shaft-washer bore, 270 mm outside diameter, 67 mm stack height (6.299 x 10.63 x 2.638 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 915 kN, C0a 2860 kN and a 223 kN fatigue load limit Pu; limiting speed 1,300 r/min with oil lubrication; mass about 15900 g."
      },
      {
        "q": "How is the 29332 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 32 encodes the 160 mm bore (bore code x 5). The 270 mm OD and 67 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29332 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,300 r/min, for 29332?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29332?",
        "a": "The 160/270/67 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 915 kN / C0a 2860 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29332-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×270×67 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29332"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29432",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29432",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 160,
    "D_mm": 320,
    "B_mm": 95,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 1670,
    "static_load_kN": 5150,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 320,
    "limiting_speed_rpm": 1000,
    "max_rpm": 1000,
    "speed_oil_rpm": 1000,
    "weight_g": 37000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The heavy-section 29400 spherical-thrust family entry 29432 combines a spherical housing-washer raceway with asymmetric barrel rollers in 95 mm of stack height. Reading the code: 294 is the dimension series (heavy-section 29400 spherical-thrust family), and 32 encodes the 160 mm bore (bore code x 5). The single printed speed, 1,000 r/min, is an oil-lubrication figure: the catalogue greases these bearings only for the smallest duties, and this size is rated for oil. Choose the heavy-section 29400 spherical-thrust family when heavy thrust meets misalignment: vertical turbines, mills and slew pivots are the classic homes. The 160 mm shaft washer normally mounts with a tight shaft fit; support the housing washer so it stays free to align on its spherical seat. ",
    "applications": [
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation",
      "fretting on the shaft seat after the washer crept under reversing axial shock"
    ],
    "pitfalls": [
      "At 160 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 294 heavy section tops the plan at this bore with the largest 320 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Shock thrust above C0a 5150 kN leaves contact dents that seed fatigue; screwdown and press duties need the static check first.",
      "Oil-bath level is set for the cage, not the housing: too low starves the contact, too high churns heat at the 1,000 r/min end of the range.",
      "Oil-bath level is set for the cage, not the housing: too low starves the contact, too high churns heat at the 1,000 r/min end of the range.",
      "The Ca 1670/C0a 5150 kN ratings and 320 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29432; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29432?",
        "a": "29432 is a spherical roller thrust bearing to ISO 104: 160 mm shaft-washer bore, 320 mm outside diameter, 95 mm stack height (6.299 x 12.598 x 3.74 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1670 kN, C0a 5150 kN and a 320 kN fatigue load limit Pu; limiting speed 1,000 r/min with oil lubrication; mass about 37000 g."
      },
      {
        "q": "How is the 29432 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 32 encodes the 160 mm bore (bore code x 5). The 320 mm OD and 95 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29432 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,000 r/min, for 29432?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29432?",
        "a": "The 160/320/95 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1670 kN / C0a 5150 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29432-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×320×95 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=228",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29432"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29234",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29234",
    "series": "29200-series",
    "type": "spherical_roller_thrust",
    "d_mm": 170,
    "D_mm": 240,
    "B_mm": 42,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 475,
    "static_load_kN": 1770,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 146,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 1600,
    "weight_g": 6020,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 29234 appears as a light-section 29200 spherical-thrust family bearing with a 170 mm shaft washer, 240 mm across the housing washer and 42 mm of height. The designation is 292 is the dimension series (light-section 29200 spherical-thrust family) plus 34 encodes the 170 mm bore (bore code x 5). NTN prints 475 kN axial dynamic and 1770 kN axial static for this size and a 146 kN fatigue load limit Pu. Minimum axial load matters here too: at speed the rollers skid on a lightly loaded bearing, so check the catalogue minimum-load formula before downsizing the thrust spring. On vertical shafts, confirm the minimum axial load from the rotor weight plus any spring preload before the first run at speed. ",
    "applications": [
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "fretting on the shaft seat after the washer crept under reversing axial shock",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue"
    ],
    "pitfalls": [
      "At 170 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 292 light section is the speed-and-space end of the spherical-thrust plan — for the same 170 mm bore it trades capacity for a smaller 240 mm OD and lower height.",
      "The C0a of 1770 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.",
      "Mixing washers between bearings during overhaul is a real risk at this size — rollers and raceways run in together, so keep each 29234 stack as a set.",
      "Mixing washers between bearings during overhaul is a real risk at this size — rollers and raceways run in together, so keep each 29234 stack as a set.",
      "The Ca 475/C0a 1770 kN ratings and 146 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29234; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29234?",
        "a": "29234 is a spherical roller thrust bearing to ISO 104: 170 mm shaft-washer bore, 240 mm outside diameter, 42 mm stack height (6.693 x 9.449 x 1.654 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 475 kN, C0a 1770 kN and a 146 kN fatigue load limit Pu; limiting speed 1,600 r/min with oil lubrication; mass about 6020 g."
      },
      {
        "q": "How is the 29234 designation structured?",
        "a": "292 is the dimension series (light-section 29200 spherical-thrust family); 34 encodes the 170 mm bore (bore code x 5). The 240 mm OD and 42 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29234 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,600 r/min, for 29234?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29234?",
        "a": "The 170/240/42 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 475 kN / C0a 1770 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29234",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29234"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29334",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29334",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 170,
    "D_mm": 280,
    "B_mm": 67,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 950,
    "static_load_kN": 3050,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 238,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1200,
    "weight_g": 16600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The medium-section 29300 spherical-thrust family entry 29334 combines a spherical housing-washer raceway with asymmetric barrel rollers in 67 mm of stack height. NTN builds the number from 293 is the dimension series (medium-section 29300 spherical-thrust family); 34 encodes the 170 mm bore (bore code x 5). The spherical housing raceway lets the shaft washer align itself as the seats settle — the property that keeps the 3050 kN static rating honest in real housings. Selection starts from the load case: axial must dominate, and any radial share must stay within the catalogue combined-load rule while the bearing self-aligns. On vertical shafts, confirm the minimum axial load from the rotor weight plus any spring preload before the first run at speed. ",
    "applications": [
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact"
    ],
    "pitfalls": [
      "At 170 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 170 mm bore.",
      "Below the minimum axial load the rollers skid; at 1,200 r/min the Ca of 950 kN never comes into play before the raceway is smeared.",
      "Oil-bath level is set for the cage, not the housing: too low starves the contact, too high churns heat at the 1,200 r/min end of the range.",
      "Do not let the self-aligning travel absorb a bent shaft: the bearing aligns to seats, not to a shaft that whips.",
      "The Ca 950/C0a 3050 kN ratings and 238 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29334; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29334?",
        "a": "29334 is a spherical roller thrust bearing to ISO 104: 170 mm shaft-washer bore, 280 mm outside diameter, 67 mm stack height (6.693 x 11.024 x 2.638 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 950 kN, C0a 3050 kN and a 238 kN fatigue load limit Pu; limiting speed 1,200 r/min with oil lubrication; mass about 16600 g."
      },
      {
        "q": "How is the 29334 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 34 encodes the 170 mm bore (bore code x 5). The 280 mm OD and 67 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29334 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,200 r/min, for 29334?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29334?",
        "a": "The 170/280/67 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 950 kN / C0a 3050 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29334-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 170×280×67 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29334"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29434",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29434",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 170,
    "D_mm": 340,
    "B_mm": 103,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 1840,
    "static_load_kN": 5750,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 345,
    "limiting_speed_rpm": 940,
    "max_rpm": 940,
    "speed_oil_rpm": 940,
    "weight_g": 45000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29434 is the 170 mm member of NTN's heavy-section 29400 spherical-thrust family: 340 mm over the housing washer, 103 mm tall. Decoding 29434: 294 is the dimension series (heavy-section 29400 spherical-thrust family), with 34 encodes the 170 mm bore (bore code x 5). The static/dynamic ratio of 3.13 tells the story of a roller raceway: enormous reserve for slow, shocked or oscillating thrust. The 170/340/103 envelope follows ISO 104, so dimensional interchange holds between makers; osculation, roller profile and ratings do not automatically follow. Check face runout of the support surfaces before assembly: the self-aligning feature absorbs steady misalignment, not a rocking seat. ",
    "applications": [
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces"
    ],
    "pitfalls": [
      "At 170 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 294 heavy section tops the plan at this bore with the largest 340 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "Shock thrust above C0a 5750 kN leaves contact dents that seed fatigue; screwdown and press duties need the static check first.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "The Ca 1840/C0a 5750 kN ratings and 345 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29434; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29434?",
        "a": "29434 is a spherical roller thrust bearing to ISO 104: 170 mm shaft-washer bore, 340 mm outside diameter, 103 mm stack height (6.693 x 13.386 x 4.055 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1840 kN, C0a 5750 kN and a 345 kN fatigue load limit Pu; limiting speed 940 r/min with oil lubrication; mass about 45000 g."
      },
      {
        "q": "How is the 29434 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 34 encodes the 170 mm bore (bore code x 5). The 340 mm OD and 103 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29434 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 940 r/min, for 29434?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29434?",
        "a": "The 170/340/103 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1840 kN / C0a 5750 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29434-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 170×340×103 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29434"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29236",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29236",
    "series": "29200-series",
    "type": "spherical_roller_thrust",
    "d_mm": 180,
    "D_mm": 250,
    "B_mm": 42,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 500,
    "static_load_kN": 1920,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 160,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 1600,
    "weight_g": 6270,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The light-section 29200 spherical-thrust family entry 29236 combines a spherical housing-washer raceway with asymmetric barrel rollers in 42 mm of stack height. Two fields make up the code — 292 is the dimension series (light-section 29200 spherical-thrust family) and 36 encodes the 180 mm bore (bore code x 5). Asymmetric rollers and the angled contact mean the bearing also tolerates radial load — the catalogue allows a radial share while axial load clearly dominates. Within the spherical-thrust plan, 292 is the light section and 294 the heavy one; stepping up from a 292 to a 294 at the same bore roughly doubles the C0a class. The 180 mm shaft washer normally mounts with a tight shaft fit; support the housing washer so it stays free to align on its spherical seat. ",
    "applications": [
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation"
    ],
    "pitfalls": [
      "At 180 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 292 light section is the speed-and-space end of the spherical-thrust plan — for the same 180 mm bore it trades capacity for a smaller 250 mm OD and lower height.",
      "The 42 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "The 42 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "Shock thrust above C0a 1920 kN leaves contact dents that seed fatigue; screwdown and press duties need the static check first.",
      "The Ca 500/C0a 1920 kN ratings and 160 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29236; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29236?",
        "a": "29236 is a spherical roller thrust bearing to ISO 104: 180 mm shaft-washer bore, 250 mm outside diameter, 42 mm stack height (7.087 x 9.843 x 1.654 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 500 kN, C0a 1920 kN and a 160 kN fatigue load limit Pu; limiting speed 1,600 r/min with oil lubrication; mass about 6270 g."
      },
      {
        "q": "How is the 29236 designation structured?",
        "a": "292 is the dimension series (light-section 29200 spherical-thrust family); 36 encodes the 180 mm bore (bore code x 5). The 250 mm OD and 42 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29236 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,600 r/min, for 29236?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29236?",
        "a": "The 180/250/42 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 500 kN / C0a 1920 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29236-E",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29236"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29336",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29336",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 180,
    "D_mm": 300,
    "B_mm": 73,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 1110,
    "static_load_kN": 3600,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 272,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1100,
    "weight_g": 21200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29336 is the 180 mm member of NTN's medium-section 29300 spherical-thrust family: 300 mm over the housing washer, 73 mm tall. Reading the code: 293 is the dimension series (medium-section 29300 spherical-thrust family), and 36 encodes the 180 mm bore (bore code x 5). Catalogue mass is about 21 kg for the full washer-and-roller stack. Minimum axial load matters here too: at speed the rollers skid on a lightly loaded bearing, so check the catalogue minimum-load formula before downsizing the thrust spring. The 180 mm shaft washer normally mounts with a tight shaft fit; support the housing washer so it stays free to align on its spherical seat. ",
    "applications": [
      "rotary kiln and furnace thrust positions",
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "fretting on the shaft seat after the washer crept under reversing axial shock",
      "fretting on the shaft seat after the washer crept under reversing axial shock"
    ],
    "pitfalls": [
      "At 180 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 180 mm bore.",
      "Oil-bath level is set for the cage, not the housing: too low starves the contact, too high churns heat at the 1,100 r/min end of the range.",
      "Shock thrust above C0a 3600 kN leaves contact dents that seed fatigue; screwdown and press duties need the static check first.",
      "The 73 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "The Ca 1110/C0a 3600 kN ratings and 272 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29336; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29336?",
        "a": "29336 is a spherical roller thrust bearing to ISO 104: 180 mm shaft-washer bore, 300 mm outside diameter, 73 mm stack height (7.087 x 11.811 x 2.874 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1110 kN, C0a 3600 kN and a 272 kN fatigue load limit Pu; limiting speed 1,100 r/min with oil lubrication; mass about 21200 g."
      },
      {
        "q": "How is the 29336 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 36 encodes the 180 mm bore (bore code x 5). The 300 mm OD and 73 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29336 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,100 r/min, for 29336?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29336?",
        "a": "The 180/300/73 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1110 kN / C0a 3600 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29336-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 180×300×73 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29336"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29436",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29436",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 180,
    "D_mm": 360,
    "B_mm": 109,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 2050,
    "static_load_kN": 6200,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 400,
    "limiting_speed_rpm": 890,
    "max_rpm": 890,
    "speed_oil_rpm": 890,
    "weight_g": 52900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29436 is an NTN spherical roller thrust bearing of the heavy-section 29400 spherical-thrust family: 180 mm bore, 360 mm outside diameter, 109 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. The designation is 294 is the dimension series (heavy-section 29400 spherical-thrust family) plus 36 encodes the 180 mm bore (bore code x 5). At 109 mm of height the bearing packs the heavy-section capacity into a stack far shorter than a comparable multi-row ball arrangement. Against a thrust ball bearing of the same 180 mm bore, this bearing carries many times the load at lower speed — the trade is oil lubrication and price. After filling with oil, rotate slowly and watch torque and temperature; a misrouted oil feed shows up in the first minutes of running. ",
    "applications": [
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions",
      "large vertical mill and crusher main shafts"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue"
    ],
    "pitfalls": [
      "At 180 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 294 heavy section tops the plan at this bore with the largest 360 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Mixing washers between bearings during overhaul is a real risk at this size — rollers and raceways run in together, so keep each 29436 stack as a set.",
      "Self-aligning does not mean self-locating: the housing washer must stay free on its spherical seat — clamping it flat destroys the feature the 29436 was chosen for.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "The Ca 2050/C0a 6200 kN ratings and 400 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29436; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29436?",
        "a": "29436 is a spherical roller thrust bearing to ISO 104: 180 mm shaft-washer bore, 360 mm outside diameter, 109 mm stack height (7.087 x 14.173 x 4.291 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 2050 kN, C0a 6200 kN and a 400 kN fatigue load limit Pu; limiting speed 890 r/min with oil lubrication; mass about 52900 g."
      },
      {
        "q": "How is the 29436 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 36 encodes the 180 mm bore (bore code x 5). The 360 mm OD and 109 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29436 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 890 r/min, for 29436?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29436?",
        "a": "The 180/360/109 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 2050 kN / C0a 6200 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29436-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 180×360×109 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29436"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29238",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29238",
    "series": "29200-series",
    "type": "spherical_roller_thrust",
    "d_mm": 190,
    "D_mm": 270,
    "B_mm": 48,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 585,
    "static_load_kN": 2230,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 184,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1400,
    "weight_g": 8800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29238 is the 190 mm member of NTN's light-section 29200 spherical-thrust family: 270 mm over the housing washer, 48 mm tall. NTN builds the number from 292 is the dimension series (light-section 29200 spherical-thrust family); 38 encodes the 190 mm bore (bore code x 5). A machined cage guided on the shaft-washer sleeve keeps the roller set spaced at the 1,400 r/min oil rating. For oscillating or slow heavy duty, size from C0a 2230 kN with the static safety factor rather than from the life equation. Check face runout of the support surfaces before assembly: the self-aligning feature absorbs steady misalignment, not a rocking seat. ",
    "applications": [
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions",
      "large vertical mill and crusher main shafts"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact"
    ],
    "pitfalls": [
      "At 190 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 292 light section is the speed-and-space end of the spherical-thrust plan — for the same 190 mm bore it trades capacity for a smaller 270 mm OD and lower height.",
      "Oil is not optional at this rating: the 1,400 r/min figure assumes oil lubrication, and a grease conversion is a redesign, not a fill change.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "Oil is not optional at this rating: the 1,400 r/min figure assumes oil lubrication, and a grease conversion is a redesign, not a fill change.",
      "The Ca 585/C0a 2230 kN ratings and 184 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29238; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29238?",
        "a": "29238 is a spherical roller thrust bearing to ISO 104: 190 mm shaft-washer bore, 270 mm outside diameter, 48 mm stack height (7.48 x 10.63 x 1.89 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 585 kN, C0a 2230 kN and a 184 kN fatigue load limit Pu; limiting speed 1,400 r/min with oil lubrication; mass about 8800 g."
      },
      {
        "q": "How is the 29238 designation structured?",
        "a": "292 is the dimension series (light-section 29200 spherical-thrust family); 38 encodes the 190 mm bore (bore code x 5). The 270 mm OD and 48 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29238 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,400 r/min, for 29238?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29238?",
        "a": "The 190/270/48 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 585 kN / C0a 2230 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29238",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29238"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29338",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29338",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 190,
    "D_mm": 320,
    "B_mm": 78,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 1280,
    "static_load_kN": 4250,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 294,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1100,
    "weight_g": 26000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29338 is an NTN spherical roller thrust bearing of the medium-section 29300 spherical-thrust family: 190 mm bore, 320 mm outside diameter, 78 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. Decoding 29338: 293 is the dimension series (medium-section 29300 spherical-thrust family), with 38 encodes the 190 mm bore (bore code x 5). Shaft and housing washers separate, so the 190 mm shaft washer can be mounted on the shaft before the roller set and housing washer follow. Within the spherical-thrust plan, 292 is the light section and 294 the heavy one; stepping up from a 292 to a 294 at the same bore roughly doubles the C0a class. Check face runout of the support surfaces before assembly: the self-aligning feature absorbs steady misalignment, not a rocking seat. ",
    "applications": [
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces"
    ],
    "pitfalls": [
      "At 190 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 190 mm bore.",
      "Self-aligning does not mean self-locating: the housing washer must stay free on its spherical seat — clamping it flat destroys the feature the 29338 was chosen for.",
      "Self-aligning does not mean self-locating: the housing washer must stay free on its spherical seat — clamping it flat destroys the feature the 29338 was chosen for.",
      "Self-aligning does not mean self-locating: the housing washer must stay free on its spherical seat — clamping it flat destroys the feature the 29338 was chosen for.",
      "The Ca 1280/C0a 4250 kN ratings and 294 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29338; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29338?",
        "a": "29338 is a spherical roller thrust bearing to ISO 104: 190 mm shaft-washer bore, 320 mm outside diameter, 78 mm stack height (7.48 x 12.598 x 3.071 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1280 kN, C0a 4250 kN and a 294 kN fatigue load limit Pu; limiting speed 1,100 r/min with oil lubrication; mass about 26000 g."
      },
      {
        "q": "How is the 29338 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 38 encodes the 190 mm bore (bore code x 5). The 320 mm OD and 78 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29338 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,100 r/min, for 29338?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29338?",
        "a": "The 190/320/78 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1280 kN / C0a 4250 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29338-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 190×320×78 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29338"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29438",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29438",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 190,
    "D_mm": 380,
    "B_mm": 115,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 2230,
    "static_load_kN": 6800,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 430,
    "limiting_speed_rpm": 840,
    "max_rpm": 840,
    "speed_oil_rpm": 840,
    "weight_g": 62000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 29438 belongs to the heavy-section 29400 spherical-thrust family of spherical roller thrust bearings: 190 / 380 / 115 mm (bore / OD / height). Two fields make up the code — 294 is the dimension series (heavy-section 29400 spherical-thrust family) and 38 encodes the 190 mm bore (bore code x 5). The spherical housing raceway lets the shaft washer align itself as the seats settle — the property that keeps the 6800 kN static rating honest in real housings. If speed climbs toward the 840 r/min oil rating, the lubrication design — bath, circulation, cooling — becomes the real selection criterion. Lift the bearing by the washers, never through the roller set; a 62 kg stack punishes improvisation. ",
    "applications": [
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation"
    ],
    "pitfalls": [
      "At 190 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 294 heavy section tops the plan at this bore with the largest 380 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "Do not let the self-aligning travel absorb a bent shaft: the bearing aligns to seats, not to a shaft that whips.",
      "The Ca 2230/C0a 6800 kN ratings and 430 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29438; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29438?",
        "a": "29438 is a spherical roller thrust bearing to ISO 104: 190 mm shaft-washer bore, 380 mm outside diameter, 115 mm stack height (7.48 x 14.961 x 4.528 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 2230 kN, C0a 6800 kN and a 430 kN fatigue load limit Pu; limiting speed 840 r/min with oil lubrication; mass about 62000 g."
      },
      {
        "q": "How is the 29438 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 38 encodes the 190 mm bore (bore code x 5). The 380 mm OD and 115 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29438 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 840 r/min, for 29438?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29438?",
        "a": "The 190/380/115 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 2230 kN / C0a 6800 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29438-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 190×380×115 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29438"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29240",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29240",
    "series": "29200-series",
    "type": "spherical_roller_thrust",
    "d_mm": 200,
    "D_mm": 280,
    "B_mm": 48,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 595,
    "static_load_kN": 2300,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 183,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 1400,
    "weight_g": 9140,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29240 is an NTN spherical roller thrust bearing of the light-section 29200 spherical-thrust family: 200 mm bore, 280 mm outside diameter, 48 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. Decoding 29240: 292 is the dimension series (light-section 29200 spherical-thrust family), with 40 encodes the 200 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 595 kN against C0a 2300 kN — the roller contact line is why a 200 mm bore here out-carries any thrust ball bearing of the same size. Minimum axial load matters here too: at speed the rollers skid on a lightly loaded bearing, so check the catalogue minimum-load formula before downsizing the thrust spring. The 200 mm shaft washer normally mounts with a tight shaft fit; support the housing washer so it stays free to align on its spherical seat. ",
    "applications": [
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "fretting on the shaft seat after the washer crept under reversing axial shock",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces"
    ],
    "pitfalls": [
      "At 200 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 292 light section is the speed-and-space end of the spherical-thrust plan — for the same 200 mm bore it trades capacity for a smaller 280 mm OD and lower height.",
      "The C0a of 2300 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.",
      "Oil is not optional at this rating: the 1,400 r/min figure assumes oil lubrication, and a grease conversion is a redesign, not a fill change.",
      "Below the minimum axial load the rollers skid; at 1,400 r/min the Ca of 595 kN never comes into play before the raceway is smeared.",
      "The Ca 595/C0a 2300 kN ratings and 183 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29240; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29240?",
        "a": "29240 is a spherical roller thrust bearing to ISO 104: 200 mm shaft-washer bore, 280 mm outside diameter, 48 mm stack height (7.874 x 11.024 x 1.89 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 595 kN, C0a 2300 kN and a 183 kN fatigue load limit Pu; limiting speed 1,400 r/min with oil lubrication; mass about 9140 g."
      },
      {
        "q": "How is the 29240 designation structured?",
        "a": "292 is the dimension series (light-section 29200 spherical-thrust family); 40 encodes the 200 mm bore (bore code x 5). The 280 mm OD and 48 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29240 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,400 r/min, for 29240?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29240?",
        "a": "The 200/280/48 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 595 kN / C0a 2300 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29240-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 200×280×48 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29240"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29340",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29340",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 200,
    "D_mm": 340,
    "B_mm": 85,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 1420,
    "static_load_kN": 4600,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 330,
    "limiting_speed_rpm": 980,
    "max_rpm": 980,
    "speed_oil_rpm": 980,
    "weight_g": 31900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 29340 belongs to the medium-section 29300 spherical-thrust family of spherical roller thrust bearings: 200 / 340 / 85 mm (bore / OD / height). Two fields make up the code — 293 is the dimension series (medium-section 29300 spherical-thrust family) and 40 encodes the 200 mm bore (bore code x 5). At 85 mm of height the bearing packs the medium-section capacity into a stack far shorter than a comparable multi-row ball arrangement. Selection starts from the load case: axial must dominate, and any radial share must stay within the catalogue combined-load rule while the bearing self-aligns. The 200 mm shaft washer normally mounts with a tight shaft fit; support the housing washer so it stays free to align on its spherical seat. ",
    "applications": [
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation"
    ],
    "pitfalls": [
      "At 200 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 200 mm bore.",
      "Below the minimum axial load the rollers skid; at 980 r/min the Ca of 1420 kN never comes into play before the raceway is smeared.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "The Ca 1420/C0a 4600 kN ratings and 330 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29340; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29340?",
        "a": "29340 is a spherical roller thrust bearing to ISO 104: 200 mm shaft-washer bore, 340 mm outside diameter, 85 mm stack height (7.874 x 13.386 x 3.346 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1420 kN, C0a 4600 kN and a 330 kN fatigue load limit Pu; limiting speed 980 r/min with oil lubrication; mass about 31900 g."
      },
      {
        "q": "How is the 29340 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 40 encodes the 200 mm bore (bore code x 5). The 340 mm OD and 85 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29340 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 980 r/min, for 29340?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29340?",
        "a": "The 200/340/85 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1420 kN / C0a 4600 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29340-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 200×340×85 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29340"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29440",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29440",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 200,
    "D_mm": 400,
    "B_mm": 122,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 2490,
    "static_load_kN": 7650,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 465,
    "limiting_speed_rpm": 790,
    "max_rpm": 790,
    "speed_oil_rpm": 790,
    "weight_g": 73300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 200 x 400 x 122 mm, NTN 29440 sits in the heavy-section 29400 spherical-thrust family of the spherical-thrust programme. Reading the code: 294 is the dimension series (heavy-section 29400 spherical-thrust family), and 40 encodes the 200 mm bore (bore code x 5). The single printed speed, 790 r/min, is an oil-lubrication figure: the catalogue greases these bearings only for the smallest duties, and this size is rated for oil. The 200/400/122 envelope follows ISO 104, so dimensional interchange holds between makers; osculation, roller profile and ratings do not automatically follow. After filling with oil, rotate slowly and watch torque and temperature; a misrouted oil feed shows up in the first minutes of running. ",
    "applications": [
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces",
      "fretting on the shaft seat after the washer crept under reversing axial shock"
    ],
    "pitfalls": [
      "At 200 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 294 heavy section tops the plan at this bore with the largest 400 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "The C0a of 7650 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.",
      "Oil-bath level is set for the cage, not the housing: too low starves the contact, too high churns heat at the 790 r/min end of the range.",
      "The Ca 2490/C0a 7650 kN ratings and 465 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29440; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29440?",
        "a": "29440 is a spherical roller thrust bearing to ISO 104: 200 mm shaft-washer bore, 400 mm outside diameter, 122 mm stack height (7.874 x 15.748 x 4.803 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 2490 kN, C0a 7650 kN and a 465 kN fatigue load limit Pu; limiting speed 790 r/min with oil lubrication; mass about 73300 g."
      },
      {
        "q": "How is the 29440 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 40 encodes the 200 mm bore (bore code x 5). The 400 mm OD and 122 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29440 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 790 r/min, for 29440?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29440?",
        "a": "The 200/400/122 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 2490 kN / C0a 7650 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29440-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 200×400×122 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29440"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29244",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29244",
    "series": "29200-series",
    "type": "spherical_roller_thrust",
    "d_mm": 220,
    "D_mm": 300,
    "B_mm": 48,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 620,
    "static_load_kN": 2480,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 198,
    "limiting_speed_rpm": 1300,
    "max_rpm": 1300,
    "speed_oil_rpm": 1300,
    "weight_g": 9940,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 220 x 300 x 48 mm, NTN 29244 sits in the light-section 29200 spherical-thrust family of the spherical-thrust programme. Two fields make up the code — 292 is the dimension series (light-section 29200 spherical-thrust family) and 44 encodes the 220 mm bore (bore code x 5). Asymmetric rollers and the angled contact mean the bearing also tolerates radial load — the catalogue allows a radial share while axial load clearly dominates. For oscillating or slow heavy duty, size from C0a 2480 kN with the static safety factor rather than from the life equation. After filling with oil, rotate slowly and watch torque and temperature; a misrouted oil feed shows up in the first minutes of running. ",
    "applications": [
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions",
      "large vertical mill and crusher main shafts"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation"
    ],
    "pitfalls": [
      "At 220 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 292 light section is the speed-and-space end of the spherical-thrust plan — for the same 220 mm bore it trades capacity for a smaller 300 mm OD and lower height.",
      "Oil is not optional at this rating: the 1,300 r/min figure assumes oil lubrication, and a grease conversion is a redesign, not a fill change.",
      "Do not let the self-aligning travel absorb a bent shaft: the bearing aligns to seats, not to a shaft that whips.",
      "Shock thrust above C0a 2480 kN leaves contact dents that seed fatigue; screwdown and press duties need the static check first.",
      "The Ca 620/C0a 2480 kN ratings and 198 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29244; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29244?",
        "a": "29244 is a spherical roller thrust bearing to ISO 104: 220 mm shaft-washer bore, 300 mm outside diameter, 48 mm stack height (8.661 x 11.811 x 1.89 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 620 kN, C0a 2480 kN and a 198 kN fatigue load limit Pu; limiting speed 1,300 r/min with oil lubrication; mass about 9940 g."
      },
      {
        "q": "How is the 29244 designation structured?",
        "a": "292 is the dimension series (light-section 29200 spherical-thrust family); 44 encodes the 220 mm bore (bore code x 5). The 300 mm OD and 48 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29244 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,300 r/min, for 29244?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29244?",
        "a": "The 220/300/48 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 620 kN / C0a 2480 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29244-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 220×300×48 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29244"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29344",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29344",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 220,
    "D_mm": 360,
    "B_mm": 85,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 1540,
    "static_load_kN": 5200,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 360,
    "limiting_speed_rpm": 940,
    "max_rpm": 940,
    "speed_oil_rpm": 940,
    "weight_g": 34500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the medium-section 29300 spherical-thrust family, 29344 measures 220 mm through the shaft washer, 360 mm over the outside and 85 mm in assembled height. Reading the code: 293 is the dimension series (medium-section 29300 spherical-thrust family), and 44 encodes the 220 mm bore (bore code x 5). Catalogue mass is about 35 kg for the full washer-and-roller stack. Within the spherical-thrust plan, 292 is the light section and 294 the heavy one; stepping up from a 292 to a 294 at the same bore roughly doubles the C0a class. After filling with oil, rotate slowly and watch torque and temperature; a misrouted oil feed shows up in the first minutes of running. ",
    "applications": [
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation",
      "fretting on the shaft seat after the washer crept under reversing axial shock"
    ],
    "pitfalls": [
      "At 220 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 220 mm bore.",
      "Self-aligning does not mean self-locating: the housing washer must stay free on its spherical seat — clamping it flat destroys the feature the 29344 was chosen for.",
      "Mixing washers between bearings during overhaul is a real risk at this size — rollers and raceways run in together, so keep each 29344 stack as a set.",
      "The 85 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "The Ca 1540/C0a 5200 kN ratings and 360 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29344; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29344?",
        "a": "29344 is a spherical roller thrust bearing to ISO 104: 220 mm shaft-washer bore, 360 mm outside diameter, 85 mm stack height (8.661 x 14.173 x 3.346 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1540 kN, C0a 5200 kN and a 360 kN fatigue load limit Pu; limiting speed 940 r/min with oil lubrication; mass about 34500 g."
      },
      {
        "q": "How is the 29344 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 44 encodes the 220 mm bore (bore code x 5). The 360 mm OD and 85 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29344 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 940 r/min, for 29344?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29344?",
        "a": "The 220/360/85 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1540 kN / C0a 5200 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29344-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 220×360×85 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29344"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29444",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29444",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 220,
    "D_mm": 420,
    "B_mm": 122,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 2560,
    "static_load_kN": 8100,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 505,
    "limiting_speed_rpm": 760,
    "max_rpm": 760,
    "speed_oil_rpm": 760,
    "weight_g": 77800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 29444 appears as a heavy-section 29400 spherical-thrust family bearing with a 220 mm shaft washer, 420 mm across the housing washer and 122 mm of height. The designation is 294 is the dimension series (heavy-section 29400 spherical-thrust family) plus 44 encodes the 220 mm bore (bore code x 5). At 122 mm of height the bearing packs the heavy-section capacity into a stack far shorter than a comparable multi-row ball arrangement. If speed climbs toward the 760 r/min oil rating, the lubrication design — bath, circulation, cooling — becomes the real selection criterion. Torque the shaft nut against the shaft washer shoulder and verify axial clamping — a loose shaft washer frets the seat under 2560 kN class thrust. ",
    "applications": [
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue"
    ],
    "pitfalls": [
      "At 220 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 294 heavy section tops the plan at this bore with the largest 420 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "The 122 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "The Ca 2560/C0a 8100 kN ratings and 505 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29444; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29444?",
        "a": "29444 is a spherical roller thrust bearing to ISO 104: 220 mm shaft-washer bore, 420 mm outside diameter, 122 mm stack height (8.661 x 16.535 x 4.803 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 2560 kN, C0a 8100 kN and a 505 kN fatigue load limit Pu; limiting speed 760 r/min with oil lubrication; mass about 77800 g."
      },
      {
        "q": "How is the 29444 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 44 encodes the 220 mm bore (bore code x 5). The 420 mm OD and 122 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29444 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 760 r/min, for 29444?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29444?",
        "a": "The 220/420/122 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 2560 kN / C0a 8100 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29444-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 220×420×122 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29444"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29248-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29248",
    "series": "29200-series",
    "type": "spherical_roller_thrust",
    "d_mm": 240,
    "D_mm": 340,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 890,
    "static_load_kN": 3600,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 271,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1100,
    "weight_g": 17500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 240 x 340 x 60 mm, NTN 29248 sits in the light-section 29200 spherical-thrust family of the spherical-thrust programme. Reading the code: 292 is the dimension series (light-section 29200 spherical-thrust family), and 48 encodes the 240 mm bore (bore code x 5). At 60 mm of height the bearing packs the light-section capacity into a stack far shorter than a comparable multi-row ball arrangement. If speed climbs toward the 1,100 r/min oil rating, the lubrication design — bath, circulation, cooling — becomes the real selection criterion. The 240 mm shaft washer normally mounts with a tight shaft fit; support the housing washer so it stays free to align on its spherical seat. ",
    "applications": [
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue",
      "fretting on the shaft seat after the washer crept under reversing axial shock"
    ],
    "pitfalls": [
      "At 240 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 292 light section is the speed-and-space end of the spherical-thrust plan — for the same 240 mm bore it trades capacity for a smaller 340 mm OD and lower height.",
      "Shock thrust above C0a 3600 kN leaves contact dents that seed fatigue; screwdown and press duties need the static check first.",
      "Below the minimum axial load the rollers skid; at 1,100 r/min the Ca of 890 kN never comes into play before the raceway is smeared.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "The Ca 890/C0a 3600 kN ratings and 271 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29248; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29248?",
        "a": "29248 is a spherical roller thrust bearing to ISO 104: 240 mm shaft-washer bore, 340 mm outside diameter, 60 mm stack height (9.449 x 13.386 x 2.362 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 890 kN, C0a 3600 kN and a 271 kN fatigue load limit Pu; limiting speed 1,100 r/min with oil lubrication; mass about 17500 g."
      },
      {
        "q": "How is the 29248 designation structured?",
        "a": "292 is the dimension series (light-section 29200 spherical-thrust family); 48 encodes the 240 mm bore (bore code x 5). The 340 mm OD and 60 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29248 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,100 r/min, for 29248?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29248?",
        "a": "The 240/340/60 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 890 kN / C0a 3600 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29248",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 240×340×60 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29248",
      "29248-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29348",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29348",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 240,
    "D_mm": 380,
    "B_mm": 85,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 1530,
    "static_load_kN": 5250,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 390,
    "limiting_speed_rpm": 910,
    "max_rpm": 910,
    "speed_oil_rpm": 910,
    "weight_g": 36600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The medium-section 29300 spherical-thrust family entry 29348 combines a spherical housing-washer raceway with asymmetric barrel rollers in 85 mm of stack height. The designation is 293 is the dimension series (medium-section 29300 spherical-thrust family) plus 48 encodes the 240 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 1530 kN against C0a 5250 kN — the roller contact line is why a 240 mm bore here out-carries any thrust ball bearing of the same size. Where the shaft also needs radial location, pair this bearing with a spherical roller or cylindrical radial bearing — the thrust bearing is not a radial guide. Torque the shaft nut against the shaft washer shoulder and verify axial clamping — a loose shaft washer frets the seat under 1530 kN class thrust. ",
    "applications": [
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions",
      "large vertical mill and crusher main shafts"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue"
    ],
    "pitfalls": [
      "At 240 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 240 mm bore.",
      "The 85 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "Below the minimum axial load the rollers skid; at 910 r/min the Ca of 1530 kN never comes into play before the raceway is smeared.",
      "The Ca 1530/C0a 5250 kN ratings and 390 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29348; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29348?",
        "a": "29348 is a spherical roller thrust bearing to ISO 104: 240 mm shaft-washer bore, 380 mm outside diameter, 85 mm stack height (9.449 x 14.961 x 3.346 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1530 kN, C0a 5250 kN and a 390 kN fatigue load limit Pu; limiting speed 910 r/min with oil lubrication; mass about 36600 g."
      },
      {
        "q": "How is the 29348 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 48 encodes the 240 mm bore (bore code x 5). The 380 mm OD and 85 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29348 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 910 r/min, for 29348?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29348?",
        "a": "The 240/380/85 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1530 kN / C0a 5250 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29348-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 240×380×85 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29348"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29448",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29448",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 240,
    "D_mm": 440,
    "B_mm": 122,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 2680,
    "static_load_kN": 8700,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 530,
    "limiting_speed_rpm": 740,
    "max_rpm": 740,
    "speed_oil_rpm": 740,
    "weight_g": 82600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29448 is the 240 mm member of NTN's heavy-section 29400 spherical-thrust family: 440 mm over the housing washer, 122 mm tall. NTN builds the number from 294 is the dimension series (heavy-section 29400 spherical-thrust family); 48 encodes the 240 mm bore (bore code x 5). Catalogue mass is about 83 kg for the full washer-and-roller stack. Minimum axial load matters here too: at speed the rollers skid on a lightly loaded bearing, so check the catalogue minimum-load formula before downsizing the thrust spring. On vertical shafts, confirm the minimum axial load from the rotor weight plus any spring preload before the first run at speed. ",
    "applications": [
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact"
    ],
    "pitfalls": [
      "At 240 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 294 heavy section tops the plan at this bore with the largest 440 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Oil-bath level is set for the cage, not the housing: too low starves the contact, too high churns heat at the 740 r/min end of the range.",
      "Oil is not optional at this rating: the 740 r/min figure assumes oil lubrication, and a grease conversion is a redesign, not a fill change.",
      "The 122 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "The Ca 2680/C0a 8700 kN ratings and 530 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29448; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29448?",
        "a": "29448 is a spherical roller thrust bearing to ISO 104: 240 mm shaft-washer bore, 440 mm outside diameter, 122 mm stack height (9.449 x 17.323 x 4.803 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 2680 kN, C0a 8700 kN and a 530 kN fatigue load limit Pu; limiting speed 740 r/min with oil lubrication; mass about 82600 g."
      },
      {
        "q": "How is the 29448 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 48 encodes the 240 mm bore (bore code x 5). The 440 mm OD and 122 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29448 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 740 r/min, for 29448?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29448?",
        "a": "The 240/440/122 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 2680 kN / C0a 8700 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29448-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 240×440×122 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29448"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29252-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29252",
    "series": "29200-series",
    "type": "spherical_roller_thrust",
    "d_mm": 260,
    "D_mm": 360,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 960,
    "static_load_kN": 3950,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 296,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1100,
    "weight_g": 18600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 29252 belongs to the light-section 29200 spherical-thrust family of spherical roller thrust bearings: 260 / 360 / 60 mm (bore / OD / height). Reading the code: 292 is the dimension series (light-section 29200 spherical-thrust family), and 52 encodes the 260 mm bore (bore code x 5). With Ca 960 kN and C0a 3950 kN, each mm of bore carries about 3.69 kN of dynamic axial rating. Choose the light-section 29200 spherical-thrust family when heavy thrust meets misalignment: vertical turbines, mills and slew pivots are the classic homes. Torque the shaft nut against the shaft washer shoulder and verify axial clamping — a loose shaft washer frets the seat under 960 kN class thrust. ",
    "applications": [
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact",
      "fretting on the shaft seat after the washer crept under reversing axial shock"
    ],
    "pitfalls": [
      "At 260 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 292 light section is the speed-and-space end of the spherical-thrust plan — for the same 260 mm bore it trades capacity for a smaller 360 mm OD and lower height.",
      "The 60 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "Below the minimum axial load the rollers skid; at 1,100 r/min the Ca of 960 kN never comes into play before the raceway is smeared.",
      "The C0a of 3950 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.",
      "The Ca 960/C0a 3950 kN ratings and 296 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29252; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29252?",
        "a": "29252 is a spherical roller thrust bearing to ISO 104: 260 mm shaft-washer bore, 360 mm outside diameter, 60 mm stack height (10.236 x 14.173 x 2.362 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 960 kN, C0a 3950 kN and a 296 kN fatigue load limit Pu; limiting speed 1,100 r/min with oil lubrication; mass about 18600 g."
      },
      {
        "q": "How is the 29252 designation structured?",
        "a": "292 is the dimension series (light-section 29200 spherical-thrust family); 52 encodes the 260 mm bore (bore code x 5). The 360 mm OD and 60 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29252 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,100 r/min, for 29252?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29252?",
        "a": "The 260/360/60 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 960 kN / C0a 3950 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29252",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 260×360×60 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29252",
      "29252-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29352",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29352",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 260,
    "D_mm": 420,
    "B_mm": 95,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 1910,
    "static_load_kN": 6800,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 445,
    "limiting_speed_rpm": 810,
    "max_rpm": 810,
    "speed_oil_rpm": 810,
    "weight_g": 52000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29352 is an NTN spherical roller thrust bearing of the medium-section 29300 spherical-thrust family: 260 mm bore, 420 mm outside diameter, 95 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. Reading the code: 293 is the dimension series (medium-section 29300 spherical-thrust family), and 52 encodes the 260 mm bore (bore code x 5). Catalogue mass is about 52 kg for the full washer-and-roller stack. For oscillating or slow heavy duty, size from C0a 6800 kN with the static safety factor rather than from the life equation. Torque the shaft nut against the shaft washer shoulder and verify axial clamping — a loose shaft washer frets the seat under 1910 kN class thrust. ",
    "applications": [
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces",
      "fretting on the shaft seat after the washer crept under reversing axial shock"
    ],
    "pitfalls": [
      "At 260 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 260 mm bore.",
      "The C0a of 6800 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.",
      "Below the minimum axial load the rollers skid; at 810 r/min the Ca of 1910 kN never comes into play before the raceway is smeared.",
      "The 95 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "The Ca 1910/C0a 6800 kN ratings and 445 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29352; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29352?",
        "a": "29352 is a spherical roller thrust bearing to ISO 104: 260 mm shaft-washer bore, 420 mm outside diameter, 95 mm stack height (10.236 x 16.535 x 3.74 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1910 kN, C0a 6800 kN and a 445 kN fatigue load limit Pu; limiting speed 810 r/min with oil lubrication; mass about 52000 g."
      },
      {
        "q": "How is the 29352 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 52 encodes the 260 mm bore (bore code x 5). The 420 mm OD and 95 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29352 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 810 r/min, for 29352?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29352?",
        "a": "The 260/420/95 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1910 kN / C0a 6800 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29352-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 260×420×95 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29352"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29452",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29452",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 260,
    "D_mm": 480,
    "B_mm": 132,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 3050,
    "static_load_kN": 10000,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 610,
    "limiting_speed_rpm": 670,
    "max_rpm": 670,
    "speed_oil_rpm": 670,
    "weight_g": 108000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 29452 belongs to the heavy-section 29400 spherical-thrust family of spherical roller thrust bearings: 260 / 480 / 132 mm (bore / OD / height). The designation is 294 is the dimension series (heavy-section 29400 spherical-thrust family) plus 52 encodes the 260 mm bore (bore code x 5). At 132 mm of height the bearing packs the heavy-section capacity into a stack far shorter than a comparable multi-row ball arrangement. Selection starts from the load case: axial must dominate, and any radial share must stay within the catalogue combined-load rule while the bearing self-aligns. On vertical shafts, confirm the minimum axial load from the rotor weight plus any spring preload before the first run at speed. ",
    "applications": [
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions",
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "fretting on the shaft seat after the washer crept under reversing axial shock",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue"
    ],
    "pitfalls": [
      "At 260 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 294 heavy section tops the plan at this bore with the largest 480 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Below the minimum axial load the rollers skid; at 670 r/min the Ca of 3050 kN never comes into play before the raceway is smeared.",
      "Do not let the self-aligning travel absorb a bent shaft: the bearing aligns to seats, not to a shaft that whips.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "The Ca 3050/C0a 10000 kN ratings and 610 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29452; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29452?",
        "a": "29452 is a spherical roller thrust bearing to ISO 104: 260 mm shaft-washer bore, 480 mm outside diameter, 132 mm stack height (10.236 x 18.898 x 5.197 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 3050 kN, C0a 10000 kN and a 610 kN fatigue load limit Pu; limiting speed 670 r/min with oil lubrication; mass about 108000 g."
      },
      {
        "q": "How is the 29452 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 52 encodes the 260 mm bore (bore code x 5). The 480 mm OD and 132 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29452 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 670 r/min, for 29452?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29452?",
        "a": "The 260/480/132 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 3050 kN / C0a 10000 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29452-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 260×480×132 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29452"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29256-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29256",
    "series": "29200-series",
    "type": "spherical_roller_thrust",
    "d_mm": 280,
    "D_mm": 380,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 975,
    "static_load_kN": 4050,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 245,
    "limiting_speed_rpm": 1000,
    "max_rpm": 1000,
    "speed_oil_rpm": 1000,
    "weight_g": 19800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 29256 belongs to the light-section 29200 spherical-thrust family of spherical roller thrust bearings: 280 / 380 / 60 mm (bore / OD / height). Reading the code: 292 is the dimension series (light-section 29200 spherical-thrust family), and 56 encodes the 280 mm bore (bore code x 5). Catalogue mass is about 20 kg for the full washer-and-roller stack. If speed climbs toward the 1,000 r/min oil rating, the lubrication design — bath, circulation, cooling — becomes the real selection criterion. Check face runout of the support surfaces before assembly: the self-aligning feature absorbs steady misalignment, not a rocking seat. ",
    "applications": [
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation",
      "fretting on the shaft seat after the washer crept under reversing axial shock"
    ],
    "pitfalls": [
      "At 280 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 292 light section is the speed-and-space end of the spherical-thrust plan — for the same 280 mm bore it trades capacity for a smaller 380 mm OD and lower height.",
      "Self-aligning does not mean self-locating: the housing washer must stay free on its spherical seat — clamping it flat destroys the feature the 29256 was chosen for.",
      "Below the minimum axial load the rollers skid; at 1,000 r/min the Ca of 975 kN never comes into play before the raceway is smeared.",
      "The 60 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "The Ca 975/C0a 4050 kN ratings and 245 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29256; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29256?",
        "a": "29256 is a spherical roller thrust bearing to ISO 104: 280 mm shaft-washer bore, 380 mm outside diameter, 60 mm stack height (11.024 x 14.961 x 2.362 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 975 kN, C0a 4050 kN and a 245 kN fatigue load limit Pu; limiting speed 1,000 r/min with oil lubrication; mass about 19800 g."
      },
      {
        "q": "How is the 29256 designation structured?",
        "a": "292 is the dimension series (light-section 29200 spherical-thrust family); 56 encodes the 280 mm bore (bore code x 5). The 380 mm OD and 60 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29256 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 1,000 r/min, for 29256?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29256?",
        "a": "The 280/380/60 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 975 kN / C0a 4050 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29256",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 280×380×60 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29256",
      "29256-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29356",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29356",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 280,
    "D_mm": 440,
    "B_mm": 95,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 2010,
    "static_load_kN": 7250,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 480,
    "limiting_speed_rpm": 790,
    "max_rpm": 790,
    "speed_oil_rpm": 790,
    "weight_g": 54600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 280 x 440 x 95 mm, NTN 29356 sits in the medium-section 29300 spherical-thrust family of the spherical-thrust programme. The designation is 293 is the dimension series (medium-section 29300 spherical-thrust family) plus 56 encodes the 280 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 2010 kN against C0a 7250 kN — the roller contact line is why a 280 mm bore here out-carries any thrust ball bearing of the same size. Choose the medium-section 29300 spherical-thrust family when heavy thrust meets misalignment: vertical turbines, mills and slew pivots are the classic homes. On vertical shafts, confirm the minimum axial load from the rotor weight plus any spring preload before the first run at speed. ",
    "applications": [
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue"
    ],
    "pitfalls": [
      "At 280 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 280 mm bore.",
      "Oil is not optional at this rating: the 790 r/min figure assumes oil lubrication, and a grease conversion is a redesign, not a fill change.",
      "Oil-bath level is set for the cage, not the housing: too low starves the contact, too high churns heat at the 790 r/min end of the range.",
      "Below the minimum axial load the rollers skid; at 790 r/min the Ca of 2010 kN never comes into play before the raceway is smeared.",
      "The Ca 2010/C0a 7250 kN ratings and 480 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29356; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29356?",
        "a": "29356 is a spherical roller thrust bearing to ISO 104: 280 mm shaft-washer bore, 440 mm outside diameter, 95 mm stack height (11.024 x 17.323 x 3.74 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 2010 kN, C0a 7250 kN and a 480 kN fatigue load limit Pu; limiting speed 790 r/min with oil lubrication; mass about 54600 g."
      },
      {
        "q": "How is the 29356 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 56 encodes the 280 mm bore (bore code x 5). The 440 mm OD and 95 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29356 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 790 r/min, for 29356?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29356?",
        "a": "The 280/440/95 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 2010 kN / C0a 7250 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29356-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 280×440×95 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29356"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29456",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29456",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 280,
    "D_mm": 520,
    "B_mm": 145,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 3700,
    "static_load_kN": 12400,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 710,
    "limiting_speed_rpm": 610,
    "max_rpm": 610,
    "speed_oil_rpm": 610,
    "weight_g": 140000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the heavy-section 29400 spherical-thrust family, 29456 measures 280 mm through the shaft washer, 520 mm over the outside and 145 mm in assembled height. NTN builds the number from 294 is the dimension series (heavy-section 29400 spherical-thrust family); 56 encodes the 280 mm bore (bore code x 5). Catalogue mass is about 140 kg for the full washer-and-roller stack. Within the spherical-thrust plan, 292 is the light section and 294 the heavy one; stepping up from a 292 to a 294 at the same bore roughly doubles the C0a class. Check face runout of the support surfaces before assembly: the self-aligning feature absorbs steady misalignment, not a rocking seat. ",
    "applications": [
      "rotary kiln and furnace thrust positions",
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "flaking that started where radial load share grew past the design assumption — the bearing tolerates combined load only while axial load clearly dominates",
      "cage-pocket wear after long service with vibration at standstill, the rollers hammering the pocket surfaces",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact"
    ],
    "pitfalls": [
      "At 280 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 294 heavy section tops the plan at this bore with the largest 520 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Self-aligning does not mean self-locating: the housing washer must stay free on its spherical seat — clamping it flat destroys the feature the 29456 was chosen for.",
      "Shock thrust above C0a 12400 kN leaves contact dents that seed fatigue; screwdown and press duties need the static check first.",
      "The 145 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "The Ca 3700/C0a 12400 kN ratings and 710 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29456; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29456?",
        "a": "29456 is a spherical roller thrust bearing to ISO 104: 280 mm shaft-washer bore, 520 mm outside diameter, 145 mm stack height (11.024 x 20.472 x 5.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 3700 kN, C0a 12400 kN and a 710 kN fatigue load limit Pu; limiting speed 610 r/min with oil lubrication; mass about 140000 g."
      },
      {
        "q": "How is the 29456 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 56 encodes the 280 mm bore (bore code x 5). The 520 mm OD and 145 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29456 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 610 r/min, for 29456?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29456?",
        "a": "The 280/520/145 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 3700 kN / C0a 12400 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29456-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 280×520×145 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29456"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29260-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29260",
    "series": "29200-series",
    "type": "spherical_roller_thrust",
    "d_mm": 300,
    "D_mm": 420,
    "B_mm": 73,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 1330,
    "static_load_kN": 5350,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 385,
    "limiting_speed_rpm": 870,
    "max_rpm": 870,
    "speed_oil_rpm": 870,
    "weight_g": 30900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29260 is an NTN spherical roller thrust bearing of the light-section 29200 spherical-thrust family: 300 mm bore, 420 mm outside diameter, 73 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. Reading the code: 292 is the dimension series (light-section 29200 spherical-thrust family), and 60 encodes the 300 mm bore (bore code x 5). The static/dynamic ratio of 4.02 tells the story of a roller raceway: enormous reserve for slow, shocked or oscillating thrust. Choose the light-section 29200 spherical-thrust family when heavy thrust meets misalignment: vertical turbines, mills and slew pivots are the classic homes. Fill the housing with the specified oil to the level that reaches the cage — these bearings are oil-bath or circulation machines, not grease machines. ",
    "applications": [
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions",
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "fretting on the shaft seat after the washer crept under reversing axial shock",
      "fretting on the shaft seat after the washer crept under reversing axial shock"
    ],
    "pitfalls": [
      "At 300 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 292 light section is the speed-and-space end of the spherical-thrust plan — for the same 300 mm bore it trades capacity for a smaller 420 mm OD and lower height.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "Below the minimum axial load the rollers skid; at 870 r/min the Ca of 1330 kN never comes into play before the raceway is smeared.",
      "A spherical roller thrust bearing cannot take radial misalignment of the seats beyond its aligning travel — verify the housing geometry before blaming the bearing.",
      "The Ca 1330/C0a 5350 kN ratings and 385 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29260; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29260?",
        "a": "29260 is a spherical roller thrust bearing to ISO 104: 300 mm shaft-washer bore, 420 mm outside diameter, 73 mm stack height (11.811 x 16.535 x 2.874 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1330 kN, C0a 5350 kN and a 385 kN fatigue load limit Pu; limiting speed 870 r/min with oil lubrication; mass about 30900 g."
      },
      {
        "q": "How is the 29260 designation structured?",
        "a": "292 is the dimension series (light-section 29200 spherical-thrust family); 60 encodes the 300 mm bore (bore code x 5). The 420 mm OD and 73 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29260 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 870 r/min, for 29260?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29260?",
        "a": "The 300/420/73 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1330 kN / C0a 5350 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29260",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 300×420×73 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29260",
      "29260-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29360",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29360",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 300,
    "D_mm": 480,
    "B_mm": 109,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 2380,
    "static_load_kN": 8250,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 580,
    "limiting_speed_rpm": 700,
    "max_rpm": 700,
    "speed_oil_rpm": 700,
    "weight_g": 75800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 29360 appears as a medium-section 29300 spherical-thrust family bearing with a 300 mm shaft washer, 480 mm across the housing washer and 109 mm of height. Reading the code: 293 is the dimension series (medium-section 29300 spherical-thrust family), and 60 encodes the 300 mm bore (bore code x 5). Catalogue mass is about 76 kg for the full washer-and-roller stack. Where the shaft also needs radial location, pair this bearing with a spherical roller or cylindrical radial bearing — the thrust bearing is not a radial guide. On vertical shafts, confirm the minimum axial load from the rotor weight plus any spring preload before the first run at speed. ",
    "applications": [
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions",
      "large vertical mill and crusher main shafts"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact",
      "fretting on the shaft seat after the washer crept under reversing axial shock"
    ],
    "pitfalls": [
      "At 300 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 300 mm bore.",
      "The 109 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "Self-aligning does not mean self-locating: the housing washer must stay free on its spherical seat — clamping it flat destroys the feature the 29360 was chosen for.",
      "The 109 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "The Ca 2380/C0a 8250 kN ratings and 580 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29360; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29360?",
        "a": "29360 is a spherical roller thrust bearing to ISO 104: 300 mm shaft-washer bore, 480 mm outside diameter, 109 mm stack height (11.811 x 18.898 x 4.291 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 2380 kN, C0a 8250 kN and a 580 kN fatigue load limit Pu; limiting speed 700 r/min with oil lubrication; mass about 75800 g."
      },
      {
        "q": "How is the 29360 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 60 encodes the 300 mm bore (bore code x 5). The 480 mm OD and 109 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29360 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 700 r/min, for 29360?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29360?",
        "a": "The 300/480/109 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 2380 kN / C0a 8250 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29360-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 300×480×109 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29360"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29460",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29460",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 300,
    "D_mm": 540,
    "B_mm": 145,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 3850,
    "static_load_kN": 13200,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 735,
    "limiting_speed_rpm": 590,
    "max_rpm": 590,
    "speed_oil_rpm": 590,
    "weight_g": 147000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The heavy-section 29400 spherical-thrust family entry 29460 combines a spherical housing-washer raceway with asymmetric barrel rollers in 145 mm of stack height. The designation is 294 is the dimension series (heavy-section 29400 spherical-thrust family) plus 60 encodes the 300 mm bore (bore code x 5). At 145 mm of height the bearing packs the heavy-section capacity into a stack far shorter than a comparable multi-row ball arrangement. Minimum axial load matters here too: at speed the rollers skid on a lightly loaded bearing, so check the catalogue minimum-load formula before downsizing the thrust spring. Check face runout of the support surfaces before assembly: the self-aligning feature absorbs steady misalignment, not a rocking seat. ",
    "applications": [
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "thermal distress when oil viscosity was chosen by habit instead of the operating-temperature calculation",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue"
    ],
    "pitfalls": [
      "At 300 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 294 heavy section tops the plan at this bore with the largest 540 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "Oil-bath level is set for the cage, not the housing: too low starves the contact, too high churns heat at the 590 r/min end of the range.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "The Ca 3850/C0a 13200 kN ratings and 735 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29460; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29460?",
        "a": "29460 is a spherical roller thrust bearing to ISO 104: 300 mm shaft-washer bore, 540 mm outside diameter, 145 mm stack height (11.811 x 21.26 x 5.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 3850 kN, C0a 13200 kN and a 735 kN fatigue load limit Pu; limiting speed 590 r/min with oil lubrication; mass about 147000 g."
      },
      {
        "q": "How is the 29460 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 60 encodes the 300 mm bore (bore code x 5). The 540 mm OD and 145 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29460 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 590 r/min, for 29460?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29460?",
        "a": "The 300/540/145 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 3850 kN / C0a 13200 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29460-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 300×540×145 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29460"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29264-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29264",
    "series": "29200-series",
    "type": "spherical_roller_thrust",
    "d_mm": 320,
    "D_mm": 440,
    "B_mm": 73,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 1400,
    "static_load_kN": 5800,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 415,
    "limiting_speed_rpm": 840,
    "max_rpm": 840,
    "speed_oil_rpm": 840,
    "weight_g": 33500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29264 is an NTN spherical roller thrust bearing of the light-section 29200 spherical-thrust family: 320 mm bore, 440 mm outside diameter, 73 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. Reading the code: 292 is the dimension series (light-section 29200 spherical-thrust family), and 64 encodes the 320 mm bore (bore code x 5). Catalogue mass is about 34 kg for the full washer-and-roller stack. Minimum axial load matters here too: at speed the rollers skid on a lightly loaded bearing, so check the catalogue minimum-load formula before downsizing the thrust spring. The 320 mm shaft washer normally mounts with a tight shaft fit; support the housing washer so it stays free to align on its spherical seat. ",
    "applications": [
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots",
      "vertical hydro and pump-turbine main thrust blocks",
      "heavy rolling-mill and forging-press thrust seats"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue",
      "fretting on the shaft seat after the washer crept under reversing axial shock"
    ],
    "pitfalls": [
      "At 320 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 292 light section is the speed-and-space end of the spherical-thrust plan — for the same 320 mm bore it trades capacity for a smaller 440 mm OD and lower height.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "Axial load must dominate; letting the radial share creep up because the radial bearing wore is the quiet path to early raceway flaking.",
      "The 73 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "The Ca 1400/C0a 5800 kN ratings and 415 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29264; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29264?",
        "a": "29264 is a spherical roller thrust bearing to ISO 104: 320 mm shaft-washer bore, 440 mm outside diameter, 73 mm stack height (12.598 x 17.323 x 2.874 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 1400 kN, C0a 5800 kN and a 415 kN fatigue load limit Pu; limiting speed 840 r/min with oil lubrication; mass about 33500 g."
      },
      {
        "q": "How is the 29264 designation structured?",
        "a": "292 is the dimension series (light-section 29200 spherical-thrust family); 64 encodes the 320 mm bore (bore code x 5). The 440 mm OD and 73 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29264 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 840 r/min, for 29264?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29264?",
        "a": "The 320/440/73 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 1400 kN / C0a 5800 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29264",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 320×440×73 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29264",
      "29264-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29364",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29364",
    "series": "29300-series",
    "type": "spherical_roller_thrust",
    "d_mm": 320,
    "D_mm": 500,
    "B_mm": 109,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 2470,
    "static_load_kN": 8800,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 605,
    "limiting_speed_rpm": 680,
    "max_rpm": 680,
    "speed_oil_rpm": 680,
    "weight_g": 79900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29364 is the 320 mm member of NTN's medium-section 29300 spherical-thrust family: 500 mm over the housing washer, 109 mm tall. The designation is 293 is the dimension series (medium-section 29300 spherical-thrust family) plus 64 encodes the 320 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 2470 kN against C0a 8800 kN — the roller contact line is why a 320 mm bore here out-carries any thrust ball bearing of the same size. The 320/500/109 envelope follows ISO 104, so dimensional interchange holds between makers; osculation, roller profile and ratings do not automatically follow. Check face runout of the support surfaces before assembly: the self-aligning feature absorbs steady misalignment, not a rocking seat. ",
    "applications": [
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions",
      "large vertical mill and crusher main shafts",
      "heavy stacker/reclaimer and shiploading pivots"
    ],
    "failure_modes": [
      "edge stress and raceway flaking after the housing was machined so far out that the self-aligning travel ran out — alignment compensation is limited, not infinite",
      "oil-starvation polishing and then seizure of the cage guide bush when the bath level dropped below the cage",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "fretting on the shaft seat after the washer crept under reversing axial shock",
      "contamination denting from wear particles circulating in the oil bath — the dents seed the next round of surface fatigue"
    ],
    "pitfalls": [
      "At 320 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 293 medium section is the workhorse: balanced height and capacity for general heavy thrust duty at 320 mm bore.",
      "Do not let the self-aligning travel absorb a bent shaft: the bearing aligns to seats, not to a shaft that whips.",
      "The C0a of 8800 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.",
      "Below the minimum axial load the rollers skid; at 680 r/min the Ca of 2470 kN never comes into play before the raceway is smeared.",
      "The Ca 2470/C0a 8800 kN ratings and 605 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29364; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29364?",
        "a": "29364 is a spherical roller thrust bearing to ISO 104: 320 mm shaft-washer bore, 500 mm outside diameter, 109 mm stack height (12.598 x 19.685 x 4.291 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 2470 kN, C0a 8800 kN and a 605 kN fatigue load limit Pu; limiting speed 680 r/min with oil lubrication; mass about 79900 g."
      },
      {
        "q": "How is the 29364 designation structured?",
        "a": "293 is the dimension series (medium-section 29300 spherical-thrust family); 64 encodes the 320 mm bore (bore code x 5). The 500 mm OD and 109 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29364 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 680 r/min, for 29364?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29364?",
        "a": "The 320/500/109 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 2470 kN / C0a 8800 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29364-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 320×500×109 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29364"
    ],
    "locale_variants": {}
  },
  {
    "sku": "29464",
    "brand": "NTN",
    "manufacturer_designation": "NTN 29464",
    "series": "29400-series",
    "type": "spherical_roller_thrust",
    "d_mm": 320,
    "D_mm": 580,
    "B_mm": 155,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 4100,
    "static_load_kN": 14200,
    "cage_type": "brass",
    "fatigue_load_limit_kN": 820,
    "limiting_speed_rpm": 550,
    "max_rpm": 550,
    "speed_oil_rpm": 550,
    "weight_g": 181000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "29464 is an NTN spherical roller thrust bearing of the heavy-section 29400 spherical-thrust family: 320 mm bore, 580 mm outside diameter, 155 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. NTN builds the number from 294 is the dimension series (heavy-section 29400 spherical-thrust family); 64 encodes the 320 mm bore (bore code x 5). Catalogue mass is about 181 kg for the full washer-and-roller stack. For oscillating or slow heavy duty, size from C0a 14200 kN with the static safety factor rather than from the life equation. Lift the bearing by the washers, never through the roller set; a 181 kg stack punishes improvisation. ",
    "applications": [
      "heavy rolling-mill and forging-press thrust seats",
      "large marine propulsion thrust supports",
      "crane and excavator main slew bearings duty",
      "rotary kiln and furnace thrust positions"
    ],
    "failure_modes": [
      "cage and roller-end scoring when the shaft was forced into alignment by the bearing itself during a bent-shaft rescue",
      "roller/raceway scuffing from an interrupted oil supply — at these loads the EHL film is the only thing between rolling and smearing",
      "roller skid smearing when axial load fell below the minimum while the shaft was still turning fast",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact",
      "fatigue spalling on the shaft-washer raceway beginning at the high-stress inner end of the roller contact"
    ],
    "pitfalls": [
      "At 320 mm bore, seating geometry, oil supply and the minimum-load guarantee decide life — field improvisation on any of the three is the usual root cause.",
      "The 294 heavy section tops the plan at this bore with the largest 580 mm OD and tallest stack — confirm housing space and oil capacity before upgrading a 293 position.",
      "The C0a of 14200 kN is a static rating — sizing continuous thrust from C0a alone overstates the raceway's life.",
      "Mixing washers between bearings during overhaul is a real risk at this size — rollers and raceways run in together, so keep each 29464 stack as a set.",
      "The 155 mm stack height is part of the load path — any spacer or shim stack added under the housing washer must carry the full thrust without settling.",
      "The Ca 4100/C0a 14200 kN ratings and 820 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 29464; roller profile and osculation legitimately differ between manufacturers, so re-verify ratings, oil supply and minimum load before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 29464?",
        "a": "29464 is a spherical roller thrust bearing to ISO 104: 320 mm shaft-washer bore, 580 mm outside diameter, 155 mm stack height (12.598 x 22.835 x 6.102 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 4100 kN, C0a 14200 kN and a 820 kN fatigue load limit Pu; limiting speed 550 r/min with oil lubrication; mass about 181000 g."
      },
      {
        "q": "How is the 29464 designation structured?",
        "a": "294 is the dimension series (heavy-section 29400 spherical-thrust family); 64 encodes the 320 mm bore (bore code x 5). The 580 mm OD and 155 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 29464 handle misalignment and radial load?",
        "a": "Yes to both, with limits. The spherical housing-washer raceway lets the bearing self-align against steady seat misalignment, and the angled roller contact tolerates a radial share while axial load clearly dominates. It is not a radial bearing: shaft radial location still needs its own radial bearing."
      },
      {
        "q": "Why does NTN print only an oil speed, 550 r/min, for 29464?",
        "a": "Spherical roller thrust bearings of this size work under contact stresses that need an elastohydrodynamic oil film; grease is reserved for the smallest, slowest duties. The printed figure is the limiting speed with the catalogue oil-lubrication state — bath level, viscosity and cooling decide how close a real installation may run."
      },
      {
        "q": "What should be checked before substituting another make for 29464?",
        "a": "The 320/580/155 mm envelope is ISO 104 interchangeable, but roller profile, osculation, cage and washer details are maker-specific. Re-verify Ca 4100 kN / C0a 14200 kN, the oil speed rating and the minimum-load requirement against the donor catalogue before swapping on a rated drive."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "29464-E",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 320×580×155 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=229",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "29464"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51100",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51100",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 10,
    "D_mm": 24,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 10,
    "static_load_kN": 14,
    "fatigue_load_limit_kN": 0.63,
    "limiting_speed_rpm": 6700,
    "max_rpm": 6700,
    "speed_oil_rpm": 9500,
    "weight_g": 21,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The light-section 51100 thrust family entry 51100 stacks a shaft washer, ball-and-cage set and housing washer into 9 mm of height over a 10 mm bore. The designation is 511 is the dimension series (light-section 51100 thrust family) plus the bore code 00 maps to the 10 mm bore by the standard table. Catalogue mass is about 21 g for the full washer-and-cage stack. The 10/24/9 envelope follows ISO 104, so dimensional interchange holds between makers — raceway osculation and ratings do not automatically follow. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 24 mm OD already tilts the raceway and concentrates the 14 kN static capacity on a few balls. ",
    "applications": [
      "valve actuator and gearbox thrust seats",
      "food-machine vertical auger shafts",
      "laboratory centrifuge and mixer thrust ends",
      "small vertical pump and agitator thrust positions"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "Small thrust washers of 10 mm bore bend if the shaft shoulder is rough — check burrs before seating, and never press on the housing washer to drive the shaft washer home.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 10 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 10 kN never saves a bearing that is running too lightly loaded at 6,700 r/min.",
      "The 6,700 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "The Ca 10/C0a 14 kN ratings and 0.63 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51100; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51100?",
        "a": "51100 is a single-direction thrust ball bearing to ISO 104: 10 mm shaft-washer bore, 24 mm outside diameter, 9 mm stack height (0.394 x 0.945 x 0.354 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 10 kN, C0a 14 kN and a 0.63 kN fatigue load limit Pu; the grease limiting speed is 6,700 r/min and the oil rating 9,500 r/min; mass about 21 g."
      },
      {
        "q": "How is the 51100 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); the bore code 00 maps to the 10 mm bore by the standard table. The 24 mm OD and 9 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51100 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51100?",
        "a": "At the 6,700 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51100?",
        "a": "The 10/24/9 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 10 kN / C0a 14 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51100-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51100"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51200",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51200",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 10,
    "D_mm": 26,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 12.7,
    "static_load_kN": 17.1,
    "fatigue_load_limit_kN": 0.77,
    "limiting_speed_rpm": 5800,
    "max_rpm": 5800,
    "speed_oil_rpm": 8300,
    "weight_g": 30,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51200 is the 10 mm member of NTN's medium-section 51200 thrust family: 26 mm across the washers, 11 mm tall. NTN builds the number from 512 is the dimension series (medium-section 51200 thrust family); the bore code 00 maps to the 10 mm bore by the standard table. At 11 mm of height the stack is compact for the 10 mm bore class, trading section height for the medium-section load level. Against a thrust roller bearing of the same 10 mm bore, this bearing is cheaper, quieter and happier at speed, but carries far less load per mm of section. The shaft washer (bore 10 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "automotive steering-gear and clutch release points",
      "small crane hook and swivel-joint thrust supports",
      "valve actuator and gearbox thrust seats",
      "food-machine vertical auger shafts"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "Small thrust washers of 10 mm bore bend if the shaft shoulder is rough — check burrs before seating, and never press on the housing washer to drive the shaft washer home.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 10 mm bore.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 12.7 kN never saves a bearing that is running too lightly loaded at 5,800 r/min.",
      "The Ca 12.7/C0a 17.1 kN ratings and 0.77 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51200; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51200?",
        "a": "51200 is a single-direction thrust ball bearing to ISO 104: 10 mm shaft-washer bore, 26 mm outside diameter, 11 mm stack height (0.394 x 1.024 x 0.433 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 12.7 kN, C0a 17.1 kN and a 0.77 kN fatigue load limit Pu; the grease limiting speed is 5,800 r/min and the oil rating 8,300 r/min; mass about 30 g."
      },
      {
        "q": "How is the 51200 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); the bore code 00 maps to the 10 mm bore by the standard table. The 26 mm OD and 11 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51200 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51200?",
        "a": "At the 5,800 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51200?",
        "a": "The 10/26/11 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 12.7 kN / C0a 17.1 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51200-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51200"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51101",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51101",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 12,
    "D_mm": 26,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 10.3,
    "static_load_kN": 15.4,
    "fatigue_load_limit_kN": 0.69,
    "limiting_speed_rpm": 6400,
    "max_rpm": 6400,
    "speed_oil_rpm": 9200,
    "weight_g": 23,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 12 x 26 x 9 mm, NTN 51101 sits in the light-section 51100 thrust family of the single-direction thrust programme. Reading the code: 511 is the dimension series (light-section 51100 thrust family), and the bore code 01 maps to the 12 mm bore by the standard table. With Ca 10.3 kN and C0a 15.4 kN, each mm of shaft bore carries about 0.86 kN of dynamic axial rating. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 51101 cannot. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "laboratory centrifuge and mixer thrust ends",
      "small vertical pump and agitator thrust positions",
      "bench drill-press and tapping-machine spindles",
      "automotive steering-gear and clutch release points"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "Small thrust washers of 12 mm bore bend if the shaft shoulder is rough — check burrs before seating, and never press on the housing washer to drive the shaft washer home.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 12 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Shock thrust above C0a 15.4 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Swapping the shaft and housing washers is an easy assembly error on the 12 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "The Ca 10.3/C0a 15.4 kN ratings and 0.69 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51101; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51101?",
        "a": "51101 is a single-direction thrust ball bearing to ISO 104: 12 mm shaft-washer bore, 26 mm outside diameter, 9 mm stack height (0.472 x 1.024 x 0.354 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 10.3 kN, C0a 15.4 kN and a 0.69 kN fatigue load limit Pu; the grease limiting speed is 6,400 r/min and the oil rating 9,200 r/min; mass about 23 g."
      },
      {
        "q": "How is the 51101 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); the bore code 01 maps to the 12 mm bore by the standard table. The 26 mm OD and 9 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51101 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51101?",
        "a": "At the 6,400 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51101?",
        "a": "The 12/26/9 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 10.3 kN / C0a 15.4 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51101-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51101"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51201",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51201",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 12,
    "D_mm": 28,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 13.2,
    "static_load_kN": 19,
    "fatigue_load_limit_kN": 0.86,
    "limiting_speed_rpm": 5600,
    "max_rpm": 5600,
    "speed_oil_rpm": 8000,
    "weight_g": 34,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the medium-section 51200 thrust family, 51201 measures 12 mm through the shaft washer, 28 mm over the outside and 11 mm in assembled height. The designation is 512 is the dimension series (medium-section 51200 thrust family) plus the bore code 01 maps to the 12 mm bore by the standard table. The static margin, C0a 19 kN against Ca 13.2 kN, is what carries slow oscillating or shock thrust without permanent raceway dents. If the duty is high speed with light thrust, check the minimum axial load formula first; a too-large thrust ball bearing fails by skid long before its Ca of 13.2 kN is ever approached. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "valve actuator and gearbox thrust seats",
      "food-machine vertical auger shafts",
      "laboratory centrifuge and mixer thrust ends",
      "small vertical pump and agitator thrust positions"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "Small thrust washers of 12 mm bore bend if the shaft shoulder is rough — check burrs before seating, and never press on the housing washer to drive the shaft washer home.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 12 mm bore.",
      "The 5,600 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "The C0a of 19 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Shock thrust above C0a 19 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The Ca 13.2/C0a 19 kN ratings and 0.86 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51201; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51201?",
        "a": "51201 is a single-direction thrust ball bearing to ISO 104: 12 mm shaft-washer bore, 28 mm outside diameter, 11 mm stack height (0.472 x 1.102 x 0.433 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 13.2 kN, C0a 19 kN and a 0.86 kN fatigue load limit Pu; the grease limiting speed is 5,600 r/min and the oil rating 8,000 r/min; mass about 34 g."
      },
      {
        "q": "How is the 51201 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); the bore code 01 maps to the 12 mm bore by the standard table. The 28 mm OD and 11 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51201 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51201?",
        "a": "At the 5,600 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51201?",
        "a": "The 12/28/11 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 13.2 kN / C0a 19 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51201-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51201"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51102",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51102",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 15,
    "D_mm": 28,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 10.5,
    "static_load_kN": 16.8,
    "fatigue_load_limit_kN": 0.76,
    "limiting_speed_rpm": 6200,
    "max_rpm": 6200,
    "speed_oil_rpm": 8800,
    "weight_g": 24,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51102 is the 15 mm member of NTN's light-section 51100 thrust family: 28 mm across the washers, 9 mm tall. Two fields make up the code — 511 is the dimension series (light-section 51100 thrust family) and the bore code 02 maps to the 15 mm bore by the standard table. Because the contact points run at 90 deg to the shaft, none of the rating is available for radial load — not even incidentally. For a 15 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot. ",
    "applications": [
      "bench drill-press and tapping-machine spindles",
      "automotive steering-gear and clutch release points",
      "small crane hook and swivel-joint thrust supports",
      "valve actuator and gearbox thrust seats"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "Small thrust washers of 15 mm bore bend if the shaft shoulder is rough — check burrs before seating, and never press on the housing washer to drive the shaft washer home.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 15 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Single-direction means exactly that: thrust on 51102 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Single-direction means exactly that: thrust on 51102 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The Ca 10.5/C0a 16.8 kN ratings and 0.76 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51102; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51102?",
        "a": "51102 is a single-direction thrust ball bearing to ISO 104: 15 mm shaft-washer bore, 28 mm outside diameter, 9 mm stack height (0.591 x 1.102 x 0.354 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 10.5 kN, C0a 16.8 kN and a 0.76 kN fatigue load limit Pu; the grease limiting speed is 6,200 r/min and the oil rating 8,800 r/min; mass about 24 g."
      },
      {
        "q": "How is the 51102 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); the bore code 02 maps to the 15 mm bore by the standard table. The 28 mm OD and 9 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51102 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51102?",
        "a": "At the 6,200 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51102?",
        "a": "The 15/28/9 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 10.5 kN / C0a 16.8 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51102-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51102"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51202",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51202",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 15,
    "D_mm": 32,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 16.6,
    "static_load_kN": 24.8,
    "fatigue_load_limit_kN": 1.12,
    "limiting_speed_rpm": 5000,
    "max_rpm": 5000,
    "speed_oil_rpm": 7100,
    "weight_g": 46,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51202 is an NTN single-direction thrust ball bearing of the medium-section 51200 thrust family: 15 mm bore, 32 mm outside diameter, 12 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. Reading the code: 512 is the dimension series (medium-section 51200 thrust family), and the bore code 02 maps to the 15 mm bore by the standard table. The washer section here is 8.5 mm of radial height, and the catalogue couples it with Ca 16.6 kN / C0a 24.8 kN. Size selection ends with the minimum-load check: at the 5,000 r/min class speed, the balls need a defined axial preload to keep rolling instead of skidding. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "laboratory centrifuge and mixer thrust ends",
      "small vertical pump and agitator thrust positions",
      "bench drill-press and tapping-machine spindles",
      "automotive steering-gear and clutch release points"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "Small thrust washers of 15 mm bore bend if the shaft shoulder is rough — check burrs before seating, and never press on the housing washer to drive the shaft washer home.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 15 mm bore.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51202 stack height of 12 mm and washer set differ from the double-direction execution.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "The C0a of 24.8 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "The Ca 16.6/C0a 24.8 kN ratings and 1.12 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51202; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51202?",
        "a": "51202 is a single-direction thrust ball bearing to ISO 104: 15 mm shaft-washer bore, 32 mm outside diameter, 12 mm stack height (0.591 x 1.26 x 0.472 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 16.6 kN, C0a 24.8 kN and a 1.12 kN fatigue load limit Pu; the grease limiting speed is 5,000 r/min and the oil rating 7,100 r/min; mass about 46 g."
      },
      {
        "q": "How is the 51202 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); the bore code 02 maps to the 15 mm bore by the standard table. The 32 mm OD and 12 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51202 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51202?",
        "a": "At the 5,000 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51202?",
        "a": "The 15/32/12 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 16.6 kN / C0a 24.8 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51202-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51202"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51103",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51103",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 17,
    "D_mm": 30,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 10.8,
    "static_load_kN": 18.2,
    "fatigue_load_limit_kN": 0.82,
    "limiting_speed_rpm": 6000,
    "max_rpm": 6000,
    "speed_oil_rpm": 8500,
    "weight_g": 26,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the light-section 51100 thrust family, 51103 measures 17 mm through the shaft washer, 30 mm over the outside and 9 mm in assembled height. Decoding 51103: 511 is the dimension series (light-section 51100 thrust family), with the bore code 03 maps to the 17 mm bore by the standard table. On speed, the grease limiting speed is 6,000 r/min and the oil rating 8,500 r/min. Against a thrust roller bearing of the same 17 mm bore, this bearing is cheaper, quieter and happier at speed, but carries far less load per mm of section. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "small crane hook and swivel-joint thrust supports",
      "valve actuator and gearbox thrust seats",
      "food-machine vertical auger shafts",
      "laboratory centrifuge and mixer thrust ends"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "Small thrust washers of 17 mm bore bend if the shaft shoulder is rough — check burrs before seating, and never press on the housing washer to drive the shaft washer home.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 17 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 10.8 kN never saves a bearing that is running too lightly loaded at 6,000 r/min.",
      "The C0a of 18.2 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "The Ca 10.8/C0a 18.2 kN ratings and 0.82 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51103; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51103?",
        "a": "51103 is a single-direction thrust ball bearing to ISO 104: 17 mm shaft-washer bore, 30 mm outside diameter, 9 mm stack height (0.669 x 1.181 x 0.354 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 10.8 kN, C0a 18.2 kN and a 0.82 kN fatigue load limit Pu; the grease limiting speed is 6,000 r/min and the oil rating 8,500 r/min; mass about 26 g."
      },
      {
        "q": "How is the 51103 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); the bore code 03 maps to the 17 mm bore by the standard table. The 30 mm OD and 9 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51103 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51103?",
        "a": "At the 6,000 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51103?",
        "a": "The 17/30/9 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 10.8 kN / C0a 18.2 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51103-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×9 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51103"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51203",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51203",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 17,
    "D_mm": 35,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 17.2,
    "static_load_kN": 27.3,
    "fatigue_load_limit_kN": 1.23,
    "limiting_speed_rpm": 4800,
    "max_rpm": 4800,
    "speed_oil_rpm": 6800,
    "weight_g": 54,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51203 appears as a medium-section 51200 thrust family bearing with a 17 mm shaft washer, a 35 mm housing diameter and 12 mm of stack height. Two fields make up the code — 512 is the dimension series (medium-section 51200 thrust family) and the bore code 03 maps to the 17 mm bore by the standard table. The ball-and-cage set is separable from both washers, which is why the mounting order (shaft washer first, then cage, then housing washer) matters. Within the thrust-ball plan, 511 is the light section and 514 the heaviest for a given bore; moving up a series raises the C0a from 27.3 kN class figures at the cost of OD and height. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 35 mm OD already tilts the raceway and concentrates the 27.3 kN static capacity on a few balls. ",
    "applications": [
      "bench drill-press and tapping-machine spindles",
      "automotive steering-gear and clutch release points",
      "small crane hook and swivel-joint thrust supports",
      "valve actuator and gearbox thrust seats"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "Small thrust washers of 17 mm bore bend if the shaft shoulder is rough — check burrs before seating, and never press on the housing washer to drive the shaft washer home.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 17 mm bore.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51203 has no radial capacity at all.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51203 has no radial capacity at all.",
      "The Ca 17.2/C0a 27.3 kN ratings and 1.23 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51203; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51203?",
        "a": "51203 is a single-direction thrust ball bearing to ISO 104: 17 mm shaft-washer bore, 35 mm outside diameter, 12 mm stack height (0.669 x 1.378 x 0.472 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 17.2 kN, C0a 27.3 kN and a 1.23 kN fatigue load limit Pu; the grease limiting speed is 4,800 r/min and the oil rating 6,800 r/min; mass about 54 g."
      },
      {
        "q": "How is the 51203 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); the bore code 03 maps to the 17 mm bore by the standard table. The 35 mm OD and 12 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51203 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51203?",
        "a": "At the 4,800 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51203?",
        "a": "The 17/35/12 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 17.2 kN / C0a 27.3 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51203-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51203"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51104",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51104",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 20,
    "D_mm": 35,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 14.2,
    "static_load_kN": 24.7,
    "fatigue_load_limit_kN": 1.12,
    "limiting_speed_rpm": 5200,
    "max_rpm": 5200,
    "speed_oil_rpm": 7500,
    "weight_g": 40,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51104 is an NTN single-direction thrust ball bearing of the light-section 51100 thrust family: 20 mm bore, 35 mm outside diameter, 10 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. NTN builds the number from 511 is the dimension series (light-section 51100 thrust family); 04 encodes the 20 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 14.2 kN against C0a 24.7 kN — a static/dynamic ratio of 1.74 that is the signature of a thrust raceway. If the duty is high speed with light thrust, check the minimum axial load formula first; a too-large thrust ball bearing fails by skid long before its Ca of 14.2 kN is ever approached. The shaft washer (bore 20 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "food-machine vertical auger shafts",
      "laboratory centrifuge and mixer thrust ends",
      "small vertical pump and agitator thrust positions",
      "bench drill-press and tapping-machine spindles"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "Small thrust washers of 20 mm bore bend if the shaft shoulder is rough — check burrs before seating, and never press on the housing washer to drive the shaft washer home.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 20 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "Swapping the shaft and housing washers is an easy assembly error on the 20 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "The Ca 14.2/C0a 24.7 kN ratings and 1.12 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51104; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51104?",
        "a": "51104 is a single-direction thrust ball bearing to ISO 104: 20 mm shaft-washer bore, 35 mm outside diameter, 10 mm stack height (0.787 x 1.378 x 0.394 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 14.2 kN, C0a 24.7 kN and a 1.12 kN fatigue load limit Pu; the grease limiting speed is 5,200 r/min and the oil rating 7,500 r/min; mass about 40 g."
      },
      {
        "q": "How is the 51104 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 04 encodes the 20 mm bore (bore code x 5). The 35 mm OD and 10 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51104 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51104?",
        "a": "At the 5,200 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51104?",
        "a": "The 20/35/10 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 14.2 kN / C0a 24.7 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51104-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×35×10 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51104"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51204",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51204",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 20,
    "D_mm": 40,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 22.3,
    "static_load_kN": 37.5,
    "fatigue_load_limit_kN": 1.7,
    "limiting_speed_rpm": 4100,
    "max_rpm": 4100,
    "speed_oil_rpm": 5900,
    "weight_g": 81,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51204 belongs to the medium-section 51200 thrust family of single-direction thrust ball bearings: 20 / 40 / 14 mm (shaft bore / OD / height). Decoding 51204: 512 is the dimension series (medium-section 51200 thrust family), with 04 encodes the 20 mm bore (bore code x 5). Catalogue mass is about 81 g for the full washer-and-cage stack. Selection starts from the load direction: if thrust ever reverses, plan a second thrust bearing (or a double-direction execution) rather than relying on the unloaded raceway. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "small crane hook and swivel-joint thrust supports",
      "valve actuator and gearbox thrust seats",
      "food-machine vertical auger shafts",
      "laboratory centrifuge and mixer thrust ends"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "Small thrust washers of 20 mm bore bend if the shaft shoulder is rough — check burrs before seating, and never press on the housing washer to drive the shaft washer home.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 20 mm bore.",
      "Swapping the shaft and housing washers is an easy assembly error on the 20 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "The 4,100 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "The 4,100 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "The Ca 22.3/C0a 37.5 kN ratings and 1.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51204; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51204?",
        "a": "51204 is a single-direction thrust ball bearing to ISO 104: 20 mm shaft-washer bore, 40 mm outside diameter, 14 mm stack height (0.787 x 1.575 x 0.551 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 22.3 kN, C0a 37.5 kN and a 1.7 kN fatigue load limit Pu; the grease limiting speed is 4,100 r/min and the oil rating 5,900 r/min; mass about 81 g."
      },
      {
        "q": "How is the 51204 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 04 encodes the 20 mm bore (bore code x 5). The 40 mm OD and 14 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51204 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51204?",
        "a": "At the 4,100 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51204?",
        "a": "The 20/40/14 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 22.3 kN / C0a 37.5 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51204-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51204"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51105",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51105",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 25,
    "D_mm": 42,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 19.6,
    "static_load_kN": 37,
    "fatigue_load_limit_kN": 1.68,
    "limiting_speed_rpm": 4600,
    "max_rpm": 4600,
    "speed_oil_rpm": 6500,
    "weight_g": 60,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51105 appears as a light-section 51100 thrust family bearing with a 25 mm shaft washer, a 42 mm housing diameter and 11 mm of stack height. The designation is 511 is the dimension series (light-section 51100 thrust family) plus 05 encodes the 25 mm bore (bore code x 5). Flat-seat washers make the bearing tolerant of simple housings but demand square faces: the whole 19.6 kN rating assumes the load arrives truly axial. Size selection ends with the minimum-load check: at the 4,600 r/min class speed, the balls need a defined axial preload to keep rolling instead of skidding. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "small vertical pump and agitator thrust positions",
      "bench drill-press and tapping-machine spindles",
      "automotive steering-gear and clutch release points",
      "small crane hook and swivel-joint thrust supports"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "Small thrust washers of 25 mm bore bend if the shaft shoulder is rough — check burrs before seating, and never press on the housing washer to drive the shaft washer home.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 25 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51105 stack height of 11 mm and washer set differ from the double-direction execution.",
      "The Ca 19.6/C0a 37 kN ratings and 1.68 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51105; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51105?",
        "a": "51105 is a single-direction thrust ball bearing to ISO 104: 25 mm shaft-washer bore, 42 mm outside diameter, 11 mm stack height (0.984 x 1.654 x 0.433 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 19.6 kN, C0a 37 kN and a 1.68 kN fatigue load limit Pu; the grease limiting speed is 4,600 r/min and the oil rating 6,500 r/min; mass about 60 g."
      },
      {
        "q": "How is the 51105 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 05 encodes the 25 mm bore (bore code x 5). The 42 mm OD and 11 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51105 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51105?",
        "a": "At the 4,600 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51105?",
        "a": "The 25/42/11 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 19.6 kN / C0a 37 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51105-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51105"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51205",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51205",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 25,
    "D_mm": 47,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 27.8,
    "static_load_kN": 50.5,
    "fatigue_load_limit_kN": 2.28,
    "limiting_speed_rpm": 3700,
    "max_rpm": 3700,
    "speed_oil_rpm": 5300,
    "weight_g": 111,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The medium-section 51200 thrust family entry 51205 stacks a shaft washer, ball-and-cage set and housing washer into 15 mm of height over a 25 mm bore. NTN builds the number from 512 is the dimension series (medium-section 51200 thrust family); 05 encodes the 25 mm bore (bore code x 5). With Ca 27.8 kN and C0a 50.5 kN, each mm of shaft bore carries about 1.11 kN of dynamic axial rating. Choose the medium-section 51200 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot. ",
    "applications": [
      "food-machine vertical auger shafts",
      "laboratory centrifuge and mixer thrust ends",
      "small vertical pump and agitator thrust positions",
      "bench drill-press and tapping-machine spindles"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "Small thrust washers of 25 mm bore bend if the shaft shoulder is rough — check burrs before seating, and never press on the housing washer to drive the shaft washer home.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 25 mm bore.",
      "The C0a of 50.5 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Shock thrust above C0a 50.5 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "The Ca 27.8/C0a 50.5 kN ratings and 2.28 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51205; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51205?",
        "a": "51205 is a single-direction thrust ball bearing to ISO 104: 25 mm shaft-washer bore, 47 mm outside diameter, 15 mm stack height (0.984 x 1.85 x 0.591 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 27.8 kN, C0a 50.5 kN and a 2.28 kN fatigue load limit Pu; the grease limiting speed is 3,700 r/min and the oil rating 5,300 r/min; mass about 111 g."
      },
      {
        "q": "How is the 51205 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 05 encodes the 25 mm bore (bore code x 5). The 47 mm OD and 15 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51205 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51205?",
        "a": "At the 3,700 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51205?",
        "a": "The 25/47/15 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 27.8 kN / C0a 50.5 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51205-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51205"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51305",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51305",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 25,
    "D_mm": 52,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 35.5,
    "static_load_kN": 61.5,
    "fatigue_load_limit_kN": 2.77,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "speed_oil_rpm": 4600,
    "weight_g": 176,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51305 is the 25 mm member of NTN's heavy-section 51300 thrust family: 52 mm across the washers, 18 mm tall. Decoding 51305: 513 is the dimension series (heavy-section 51300 thrust family), with 05 encodes the 25 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 35.5 kN against C0a 61.5 kN — a static/dynamic ratio of 1.73 that is the signature of a thrust raceway. Within the thrust-ball plan, 511 is the light section and 514 the heaviest for a given bore; moving up a series raises the C0a from 61.5 kN class figures at the cost of OD and height. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot. ",
    "applications": [
      "valve actuator and gearbox thrust seats",
      "food-machine vertical auger shafts",
      "laboratory centrifuge and mixer thrust ends",
      "small vertical pump and agitator thrust positions"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "Small thrust washers of 25 mm bore bend if the shaft shoulder is rough — check burrs before seating, and never press on the housing washer to drive the shaft washer home.",
      "The 513 heavy section buys capacity with a larger 52 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51305 stack height of 18 mm and washer set differ from the double-direction execution.",
      "Swapping the shaft and housing washers is an easy assembly error on the 25 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "The Ca 35.5/C0a 61.5 kN ratings and 2.77 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51305; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51305?",
        "a": "51305 is a single-direction thrust ball bearing to ISO 104: 25 mm shaft-washer bore, 52 mm outside diameter, 18 mm stack height (0.984 x 2.047 x 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 35.5 kN, C0a 61.5 kN and a 2.77 kN fatigue load limit Pu; the grease limiting speed is 3,200 r/min and the oil rating 4,600 r/min; mass about 176 g."
      },
      {
        "q": "How is the 51305 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 05 encodes the 25 mm bore (bore code x 5). The 52 mm OD and 18 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51305 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51305?",
        "a": "At the 3,200 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51305?",
        "a": "The 25/52/18 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 35.5 kN / C0a 61.5 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51305-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51305"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51405",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51405",
    "series": "51400-series",
    "type": "thrust_ball",
    "d_mm": 25,
    "D_mm": 60,
    "B_mm": 24,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 55.5,
    "static_load_kN": 89.5,
    "fatigue_load_limit_kN": 4.05,
    "limiting_speed_rpm": 2600,
    "max_rpm": 2600,
    "speed_oil_rpm": 3700,
    "weight_g": 330,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51405 is an NTN single-direction thrust ball bearing of the extra-heavy 51400 thrust family: 25 mm bore, 60 mm outside diameter, 24 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. The designation is 514 is the dimension series (extra-heavy 51400 thrust family) plus 05 encodes the 25 mm bore (bore code x 5). Catalogue mass is about 330 g for the full washer-and-cage stack. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 51405 cannot. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "bench drill-press and tapping-machine spindles",
      "automotive steering-gear and clutch release points",
      "small crane hook and swivel-joint thrust supports",
      "valve actuator and gearbox thrust seats"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "Small thrust washers of 25 mm bore bend if the shaft shoulder is rough — check burrs before seating, and never press on the housing washer to drive the shaft washer home.",
      "The 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.",
      "Shock thrust above C0a 89.5 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51405 has no radial capacity at all.",
      "The 2,600 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "The Ca 55.5/C0a 89.5 kN ratings and 4.05 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51405; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51405?",
        "a": "51405 is a single-direction thrust ball bearing to ISO 104: 25 mm shaft-washer bore, 60 mm outside diameter, 24 mm stack height (0.984 x 2.362 x 0.945 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 55.5 kN, C0a 89.5 kN and a 4.05 kN fatigue load limit Pu; the grease limiting speed is 2,600 r/min and the oil rating 3,700 r/min; mass about 330 g."
      },
      {
        "q": "How is the 51405 designation structured?",
        "a": "514 is the dimension series (extra-heavy 51400 thrust family); 05 encodes the 25 mm bore (bore code x 5). The 60 mm OD and 24 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51405 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51405?",
        "a": "At the 2,600 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51405?",
        "a": "The 25/60/24 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 55.5 kN / C0a 89.5 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51405-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×60×24 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51405"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51106",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51106",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 30,
    "D_mm": 47,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 20.4,
    "static_load_kN": 42,
    "fatigue_load_limit_kN": 1.9,
    "limiting_speed_rpm": 4300,
    "max_rpm": 4300,
    "speed_oil_rpm": 6200,
    "weight_g": 69,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51106 belongs to the light-section 51100 thrust family of single-direction thrust ball bearings: 30 / 47 / 11 mm (shaft bore / OD / height). Reading the code: 511 is the dimension series (light-section 51100 thrust family), and 06 encodes the 30 mm bore (bore code x 5). NTN prints 20.4 kN axial dynamic and 42 kN axial static for this size and a 1.9 kN fatigue load limit Pu. Within the thrust-ball plan, 511 is the light section and 514 the heaviest for a given bore; moving up a series raises the C0a from 42 kN class figures at the cost of OD and height. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "medium crane hook blocks and slewing jibs",
      "extruder and mixer thrust housings",
      "winch and capstan vertical shafts",
      "press and punch-machine thrust seats"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 30 mm size together from unpacking to assembly.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 30 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "The 4,300 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "The 4,300 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "The Ca 20.4/C0a 42 kN ratings and 1.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51106; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51106?",
        "a": "51106 is a single-direction thrust ball bearing to ISO 104: 30 mm shaft-washer bore, 47 mm outside diameter, 11 mm stack height (1.181 x 1.85 x 0.433 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 20.4 kN, C0a 42 kN and a 1.9 kN fatigue load limit Pu; the grease limiting speed is 4,300 r/min and the oil rating 6,200 r/min; mass about 69 g."
      },
      {
        "q": "How is the 51106 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 06 encodes the 30 mm bore (bore code x 5). The 47 mm OD and 11 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51106 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51106?",
        "a": "At the 4,300 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51106?",
        "a": "The 30/47/11 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 20.4 kN / C0a 42 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51106-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51106"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51206",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51206",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 30,
    "D_mm": 52,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 29.3,
    "static_load_kN": 58,
    "fatigue_load_limit_kN": 2.63,
    "limiting_speed_rpm": 3400,
    "max_rpm": 3400,
    "speed_oil_rpm": 4900,
    "weight_g": 139,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 30 x 52 x 16 mm, NTN 51206 sits in the medium-section 51200 thrust family of the single-direction thrust programme. The designation is 512 is the dimension series (medium-section 51200 thrust family) plus 06 encodes the 30 mm bore (bore code x 5). Because the contact points run at 90 deg to the shaft, none of the rating is available for radial load — not even incidentally. The 30/52/16 envelope follows ISO 104, so dimensional interchange holds between makers — raceway osculation and ratings do not automatically follow. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "vertical motor and pump thrust shoes",
      "machine-tool tailstock and steady-rest screws",
      "medium crane hook blocks and slewing jibs",
      "extruder and mixer thrust housings"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 30 mm size together from unpacking to assembly.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 30 mm bore.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51206 stack height of 16 mm and washer set differ from the double-direction execution.",
      "Single-direction means exactly that: thrust on 51206 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The Ca 29.3/C0a 58 kN ratings and 2.63 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51206; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51206?",
        "a": "51206 is a single-direction thrust ball bearing to ISO 104: 30 mm shaft-washer bore, 52 mm outside diameter, 16 mm stack height (1.181 x 2.047 x 0.63 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 29.3 kN, C0a 58 kN and a 2.63 kN fatigue load limit Pu; the grease limiting speed is 3,400 r/min and the oil rating 4,900 r/min; mass about 139 g."
      },
      {
        "q": "How is the 51206 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 06 encodes the 30 mm bore (bore code x 5). The 52 mm OD and 16 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51206 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51206?",
        "a": "At the 3,400 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51206?",
        "a": "The 30/52/16 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 29.3 kN / C0a 58 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51206-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×52×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51206"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51306",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51306",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 30,
    "D_mm": 60,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 43,
    "static_load_kN": 78.5,
    "fatigue_load_limit_kN": 3.55,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "speed_oil_rpm": 3900,
    "weight_g": 269,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the heavy-section 51300 thrust family, 51306 measures 30 mm through the shaft washer, 60 mm over the outside and 21 mm in assembled height. NTN builds the number from 513 is the dimension series (heavy-section 51300 thrust family); 06 encodes the 30 mm bore (bore code x 5). Flat-seat washers make the bearing tolerant of simple housings but demand square faces: the whole 43 kN rating assumes the load arrives truly axial. Selection starts from the load direction: if thrust ever reverses, plan a second thrust bearing (or a double-direction execution) rather than relying on the unloaded raceway. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "conveyor vertical-drive thrust positions",
      "vertical motor and pump thrust shoes",
      "machine-tool tailstock and steady-rest screws",
      "medium crane hook blocks and slewing jibs"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 30 mm size together from unpacking to assembly.",
      "The 513 heavy section buys capacity with a larger 60 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "Single-direction means exactly that: thrust on 51306 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51306 stack height of 21 mm and washer set differ from the double-direction execution.",
      "The Ca 43/C0a 78.5 kN ratings and 3.55 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51306; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51306?",
        "a": "51306 is a single-direction thrust ball bearing to ISO 104: 30 mm shaft-washer bore, 60 mm outside diameter, 21 mm stack height (1.181 x 2.362 x 0.827 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 43 kN, C0a 78.5 kN and a 3.55 kN fatigue load limit Pu; the grease limiting speed is 2,800 r/min and the oil rating 3,900 r/min; mass about 269 g."
      },
      {
        "q": "How is the 51306 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 06 encodes the 30 mm bore (bore code x 5). The 60 mm OD and 21 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51306 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51306?",
        "a": "At the 2,800 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51306?",
        "a": "The 30/60/21 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 43 kN / C0a 78.5 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51306-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×60×21 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51306"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51406",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51406",
    "series": "51400-series",
    "type": "thrust_ball",
    "d_mm": 30,
    "D_mm": 70,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 72.5,
    "static_load_kN": 126,
    "fatigue_load_limit_kN": 5.65,
    "limiting_speed_rpm": 2200,
    "max_rpm": 2200,
    "speed_oil_rpm": 3200,
    "weight_g": 516,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51406 appears as a extra-heavy 51400 thrust family bearing with a 30 mm shaft washer, a 70 mm housing diameter and 28 mm of stack height. Reading the code: 514 is the dimension series (extra-heavy 51400 thrust family), and 06 encodes the 30 mm bore (bore code x 5). With Ca 72.5 kN and C0a 126 kN, each mm of shaft bore carries about 2.42 kN of dynamic axial rating. For a 30 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 70 mm OD already tilts the raceway and concentrates the 126 kN static capacity on a few balls. ",
    "applications": [
      "extruder and mixer thrust housings",
      "winch and capstan vertical shafts",
      "press and punch-machine thrust seats",
      "conveyor vertical-drive thrust positions"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 30 mm size together from unpacking to assembly.",
      "The 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.",
      "Single-direction means exactly that: thrust on 51406 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 72.5 kN never saves a bearing that is running too lightly loaded at 2,200 r/min.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "The Ca 72.5/C0a 126 kN ratings and 5.65 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51406; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51406?",
        "a": "51406 is a single-direction thrust ball bearing to ISO 104: 30 mm shaft-washer bore, 70 mm outside diameter, 28 mm stack height (1.181 x 2.756 x 1.102 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 72.5 kN, C0a 126 kN and a 5.65 kN fatigue load limit Pu; the grease limiting speed is 2,200 r/min and the oil rating 3,200 r/min; mass about 516 g."
      },
      {
        "q": "How is the 51406 designation structured?",
        "a": "514 is the dimension series (extra-heavy 51400 thrust family); 06 encodes the 30 mm bore (bore code x 5). The 70 mm OD and 28 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51406 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51406?",
        "a": "At the 2,200 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51406?",
        "a": "The 30/70/28 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 72.5 kN / C0a 126 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51406-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51406"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51107",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51107",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 35,
    "D_mm": 52,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 20.4,
    "static_load_kN": 44.5,
    "fatigue_load_limit_kN": 2.02,
    "limiting_speed_rpm": 3900,
    "max_rpm": 3900,
    "speed_oil_rpm": 5600,
    "weight_g": 85,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The light-section 51100 thrust family entry 51107 stacks a shaft washer, ball-and-cage set and housing washer into 12 mm of height over a 35 mm bore. Two fields make up the code — 511 is the dimension series (light-section 51100 thrust family) and 07 encodes the 35 mm bore (bore code x 5). At 12 mm of height the stack is compact for the 35 mm bore class, trading section height for the light-section load level. Selection starts from the load direction: if thrust ever reverses, plan a second thrust bearing (or a double-direction execution) rather than relying on the unloaded raceway. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 52 mm OD already tilts the raceway and concentrates the 44.5 kN static capacity on a few balls. ",
    "applications": [
      "winch and capstan vertical shafts",
      "press and punch-machine thrust seats",
      "conveyor vertical-drive thrust positions",
      "vertical motor and pump thrust shoes"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 35 mm size together from unpacking to assembly.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 35 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51107 stack height of 12 mm and washer set differ from the double-direction execution.",
      "Shock thrust above C0a 44.5 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 20.4 kN never saves a bearing that is running too lightly loaded at 3,900 r/min.",
      "The Ca 20.4/C0a 44.5 kN ratings and 2.02 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51107; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51107?",
        "a": "51107 is a single-direction thrust ball bearing to ISO 104: 35 mm shaft-washer bore, 52 mm outside diameter, 12 mm stack height (1.378 x 2.047 x 0.472 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 20.4 kN, C0a 44.5 kN and a 2.02 kN fatigue load limit Pu; the grease limiting speed is 3,900 r/min and the oil rating 5,600 r/min; mass about 85 g."
      },
      {
        "q": "How is the 51107 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 07 encodes the 35 mm bore (bore code x 5). The 52 mm OD and 12 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51107 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51107?",
        "a": "At the 3,900 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51107?",
        "a": "The 35/52/12 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 20.4 kN / C0a 44.5 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51107-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×52×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51107"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51207",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51207",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 35,
    "D_mm": 62,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 39,
    "static_load_kN": 78,
    "fatigue_load_limit_kN": 3.55,
    "limiting_speed_rpm": 2900,
    "max_rpm": 2900,
    "speed_oil_rpm": 4200,
    "weight_g": 215,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51207 is the 35 mm member of NTN's medium-section 51200 thrust family: 62 mm across the washers, 18 mm tall. Reading the code: 512 is the dimension series (medium-section 51200 thrust family), and 07 encodes the 35 mm bore (bore code x 5). On speed, the grease limiting speed is 2,900 r/min and the oil rating 4,200 r/min. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 51207 cannot. The shaft washer (bore 35 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "medium crane hook blocks and slewing jibs",
      "extruder and mixer thrust housings",
      "winch and capstan vertical shafts",
      "press and punch-machine thrust seats"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 35 mm size together from unpacking to assembly.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 35 mm bore.",
      "Shock thrust above C0a 78 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Single-direction means exactly that: thrust on 51207 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "The Ca 39/C0a 78 kN ratings and 3.55 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51207; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51207?",
        "a": "51207 is a single-direction thrust ball bearing to ISO 104: 35 mm shaft-washer bore, 62 mm outside diameter, 18 mm stack height (1.378 x 2.441 x 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 39 kN, C0a 78 kN and a 3.55 kN fatigue load limit Pu; the grease limiting speed is 2,900 r/min and the oil rating 4,200 r/min; mass about 215 g."
      },
      {
        "q": "How is the 51207 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 07 encodes the 35 mm bore (bore code x 5). The 62 mm OD and 18 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51207 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51207?",
        "a": "At the 2,900 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51207?",
        "a": "The 35/62/18 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 39 kN / C0a 78 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51207-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×18 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51207"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51307",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51307",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 35,
    "D_mm": 68,
    "B_mm": 24,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 55.5,
    "static_load_kN": 105,
    "fatigue_load_limit_kN": 4.75,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "speed_oil_rpm": 3500,
    "weight_g": 383,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51307 is an NTN single-direction thrust ball bearing of the heavy-section 51300 thrust family: 35 mm bore, 68 mm outside diameter, 24 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. The designation is 513 is the dimension series (heavy-section 51300 thrust family) plus 07 encodes the 35 mm bore (bore code x 5). NTN prints 55.5 kN axial dynamic and 105 kN axial static for this size and a 4.75 kN fatigue load limit Pu. Choose the heavy-section 51300 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. The shaft washer (bore 35 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "machine-tool tailstock and steady-rest screws",
      "medium crane hook blocks and slewing jibs",
      "extruder and mixer thrust housings",
      "winch and capstan vertical shafts"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 35 mm size together from unpacking to assembly.",
      "The 513 heavy section buys capacity with a larger 68 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "The 2,400 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51307 has no radial capacity at all.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "The Ca 55.5/C0a 105 kN ratings and 4.75 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51307; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51307?",
        "a": "51307 is a single-direction thrust ball bearing to ISO 104: 35 mm shaft-washer bore, 68 mm outside diameter, 24 mm stack height (1.378 x 2.677 x 0.945 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 55.5 kN, C0a 105 kN and a 4.75 kN fatigue load limit Pu; the grease limiting speed is 2,400 r/min and the oil rating 3,500 r/min; mass about 383 g."
      },
      {
        "q": "How is the 51307 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 07 encodes the 35 mm bore (bore code x 5). The 68 mm OD and 24 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51307 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51307?",
        "a": "At the 2,400 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51307?",
        "a": "The 35/68/24 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 55.5 kN / C0a 105 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51307-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×68×24 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51307"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51407",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51407",
    "series": "51400-series",
    "type": "thrust_ball",
    "d_mm": 35,
    "D_mm": 80,
    "B_mm": 32,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 87,
    "static_load_kN": 155,
    "fatigue_load_limit_kN": 7,
    "limiting_speed_rpm": 1900,
    "max_rpm": 1900,
    "speed_oil_rpm": 2800,
    "weight_g": 759,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51407 belongs to the extra-heavy 51400 thrust family of single-direction thrust ball bearings: 35 / 80 / 32 mm (shaft bore / OD / height). Two fields make up the code — 514 is the dimension series (extra-heavy 51400 thrust family) and 07 encodes the 35 mm bore (bore code x 5). Because the contact points run at 90 deg to the shaft, none of the rating is available for radial load — not even incidentally. Against a thrust roller bearing of the same 35 mm bore, this bearing is cheaper, quieter and happier at speed, but carries far less load per mm of section. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "press and punch-machine thrust seats",
      "conveyor vertical-drive thrust positions",
      "vertical motor and pump thrust shoes",
      "machine-tool tailstock and steady-rest screws"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 35 mm size together from unpacking to assembly.",
      "The 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 87 kN never saves a bearing that is running too lightly loaded at 1,900 r/min.",
      "Swapping the shaft and housing washers is an easy assembly error on the 35 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "Single-direction means exactly that: thrust on 51407 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The Ca 87/C0a 155 kN ratings and 7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51407; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51407?",
        "a": "51407 is a single-direction thrust ball bearing to ISO 104: 35 mm shaft-washer bore, 80 mm outside diameter, 32 mm stack height (1.378 x 3.15 x 1.26 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 87 kN, C0a 155 kN and a 7 kN fatigue load limit Pu; the grease limiting speed is 1,900 r/min and the oil rating 2,800 r/min; mass about 759 g."
      },
      {
        "q": "How is the 51407 designation structured?",
        "a": "514 is the dimension series (extra-heavy 51400 thrust family); 07 encodes the 35 mm bore (bore code x 5). The 80 mm OD and 32 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51407 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51407?",
        "a": "At the 1,900 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51407?",
        "a": "The 35/80/32 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 87 kN / C0a 155 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51407-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×32 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51407"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51108",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51108",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 40,
    "D_mm": 60,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 26.9,
    "static_load_kN": 63,
    "fatigue_load_limit_kN": 2.84,
    "limiting_speed_rpm": 3500,
    "max_rpm": 3500,
    "speed_oil_rpm": 5000,
    "weight_g": 125,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 40 x 60 x 13 mm, NTN 51108 sits in the light-section 51100 thrust family of the single-direction thrust programme. Decoding 51108: 511 is the dimension series (light-section 51100 thrust family), with 08 encodes the 40 mm bore (bore code x 5). The static margin, C0a 63 kN against Ca 26.9 kN, is what carries slow oscillating or shock thrust without permanent raceway dents. Choose the light-section 51100 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "conveyor vertical-drive thrust positions",
      "vertical motor and pump thrust shoes",
      "machine-tool tailstock and steady-rest screws",
      "medium crane hook blocks and slewing jibs"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 40 mm size together from unpacking to assembly.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 40 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51108 has no radial capacity at all.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51108 stack height of 13 mm and washer set differ from the double-direction execution.",
      "Shock thrust above C0a 63 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The Ca 26.9/C0a 63 kN ratings and 2.84 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51108; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51108?",
        "a": "51108 is a single-direction thrust ball bearing to ISO 104: 40 mm shaft-washer bore, 60 mm outside diameter, 13 mm stack height (1.575 x 2.362 x 0.512 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 26.9 kN, C0a 63 kN and a 2.84 kN fatigue load limit Pu; the grease limiting speed is 3,500 r/min and the oil rating 5,000 r/min; mass about 125 g."
      },
      {
        "q": "How is the 51108 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 08 encodes the 40 mm bore (bore code x 5). The 60 mm OD and 13 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51108 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51108?",
        "a": "At the 3,500 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51108?",
        "a": "The 40/60/13 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 26.9 kN / C0a 63 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51108-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51108"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51208",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51208",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 40,
    "D_mm": 68,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 47,
    "static_load_kN": 98.5,
    "fatigue_load_limit_kN": 4.45,
    "limiting_speed_rpm": 2700,
    "max_rpm": 2700,
    "speed_oil_rpm": 3900,
    "weight_g": 276,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the medium-section 51200 thrust family, 51208 measures 40 mm through the shaft washer, 68 mm over the outside and 19 mm in assembled height. Two fields make up the code — 512 is the dimension series (medium-section 51200 thrust family) and 08 encodes the 40 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 47 kN against C0a 98.5 kN — a static/dynamic ratio of 2.10 that is the signature of a thrust raceway. For a 40 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "winch and capstan vertical shafts",
      "press and punch-machine thrust seats",
      "conveyor vertical-drive thrust positions",
      "vertical motor and pump thrust shoes"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 40 mm size together from unpacking to assembly.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 40 mm bore.",
      "Single-direction means exactly that: thrust on 51208 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51208 has no radial capacity at all.",
      "Swapping the shaft and housing washers is an easy assembly error on the 40 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "The Ca 47/C0a 98.5 kN ratings and 4.45 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51208; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51208?",
        "a": "51208 is a single-direction thrust ball bearing to ISO 104: 40 mm shaft-washer bore, 68 mm outside diameter, 19 mm stack height (1.575 x 2.677 x 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 47 kN, C0a 98.5 kN and a 4.45 kN fatigue load limit Pu; the grease limiting speed is 2,700 r/min and the oil rating 3,900 r/min; mass about 276 g."
      },
      {
        "q": "How is the 51208 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 08 encodes the 40 mm bore (bore code x 5). The 68 mm OD and 19 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51208 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51208?",
        "a": "At the 2,700 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51208?",
        "a": "The 40/68/19 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 47 kN / C0a 98.5 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51208-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51208"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51308",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51308",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 40,
    "D_mm": 78,
    "B_mm": 26,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 69,
    "static_load_kN": 135,
    "fatigue_load_limit_kN": 6.05,
    "limiting_speed_rpm": 2200,
    "max_rpm": 2200,
    "speed_oil_rpm": 3100,
    "weight_g": 548,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51308 appears as a heavy-section 51300 thrust family bearing with a 40 mm shaft washer, a 78 mm housing diameter and 26 mm of stack height. Reading the code: 513 is the dimension series (heavy-section 51300 thrust family), and 08 encodes the 40 mm bore (bore code x 5). At 26 mm of height the stack is compact for the 40 mm bore class, trading section height for the heavy-section load level. The 40/78/26 envelope follows ISO 104, so dimensional interchange holds between makers — raceway osculation and ratings do not automatically follow. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "extruder and mixer thrust housings",
      "winch and capstan vertical shafts",
      "press and punch-machine thrust seats",
      "conveyor vertical-drive thrust positions"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 40 mm size together from unpacking to assembly.",
      "The 513 heavy section buys capacity with a larger 78 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51308 stack height of 26 mm and washer set differ from the double-direction execution.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 69 kN never saves a bearing that is running too lightly loaded at 2,200 r/min.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 69 kN never saves a bearing that is running too lightly loaded at 2,200 r/min.",
      "The Ca 69/C0a 135 kN ratings and 6.05 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51308; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51308?",
        "a": "51308 is a single-direction thrust ball bearing to ISO 104: 40 mm shaft-washer bore, 78 mm outside diameter, 26 mm stack height (1.575 x 3.071 x 1.024 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 69 kN, C0a 135 kN and a 6.05 kN fatigue load limit Pu; the grease limiting speed is 2,200 r/min and the oil rating 3,100 r/min; mass about 548 g."
      },
      {
        "q": "How is the 51308 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 08 encodes the 40 mm bore (bore code x 5). The 78 mm OD and 26 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51308 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51308?",
        "a": "At the 2,200 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51308?",
        "a": "The 40/78/26 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 69 kN / C0a 135 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51308-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×78×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51308"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51408",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51408",
    "series": "51400-series",
    "type": "thrust_ball",
    "d_mm": 40,
    "D_mm": 90,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 112,
    "static_load_kN": 205,
    "fatigue_load_limit_kN": 9.25,
    "limiting_speed_rpm": 1700,
    "max_rpm": 1700,
    "speed_oil_rpm": 2500,
    "weight_g": 1080,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The extra-heavy 51400 thrust family entry 51408 stacks a shaft washer, ball-and-cage set and housing washer into 36 mm of height over a 40 mm bore. Decoding 51408: 514 is the dimension series (extra-heavy 51400 thrust family), with 08 encodes the 40 mm bore (bore code x 5). On speed, the grease limiting speed is 1,700 r/min and the oil rating 2,500 r/min. If the duty is high speed with light thrust, check the minimum axial load formula first; a too-large thrust ball bearing fails by skid long before its Ca of 112 kN is ever approached. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot. ",
    "applications": [
      "vertical motor and pump thrust shoes",
      "machine-tool tailstock and steady-rest screws",
      "medium crane hook blocks and slewing jibs",
      "extruder and mixer thrust housings"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 40 mm size together from unpacking to assembly.",
      "The 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "The Ca 112/C0a 205 kN ratings and 9.25 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51408; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51408?",
        "a": "51408 is a single-direction thrust ball bearing to ISO 104: 40 mm shaft-washer bore, 90 mm outside diameter, 36 mm stack height (1.575 x 3.543 x 1.417 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 112 kN, C0a 205 kN and a 9.25 kN fatigue load limit Pu; the grease limiting speed is 1,700 r/min and the oil rating 2,500 r/min; mass about 1080 g."
      },
      {
        "q": "How is the 51408 designation structured?",
        "a": "514 is the dimension series (extra-heavy 51400 thrust family); 08 encodes the 40 mm bore (bore code x 5). The 90 mm OD and 36 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51408 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51408?",
        "a": "At the 1,700 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51408?",
        "a": "The 40/90/36 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 112 kN / C0a 205 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51408-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51408"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51109",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51109",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 45,
    "D_mm": 65,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 27.9,
    "static_load_kN": 69,
    "fatigue_load_limit_kN": 3.1,
    "limiting_speed_rpm": 3200,
    "max_rpm": 3200,
    "speed_oil_rpm": 4600,
    "weight_g": 148,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51109 is the 45 mm member of NTN's light-section 51100 thrust family: 65 mm across the washers, 14 mm tall. NTN builds the number from 511 is the dimension series (light-section 51100 thrust family); 09 encodes the 45 mm bore (bore code x 5). The washer section here is 10.0 mm of radial height, and the catalogue couples it with Ca 27.9 kN / C0a 69 kN. The 45/65/14 envelope follows ISO 104, so dimensional interchange holds between makers — raceway osculation and ratings do not automatically follow. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot. ",
    "applications": [
      "machine-tool tailstock and steady-rest screws",
      "medium crane hook blocks and slewing jibs",
      "extruder and mixer thrust housings",
      "winch and capstan vertical shafts"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 45 mm size together from unpacking to assembly.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 45 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Swapping the shaft and housing washers is an easy assembly error on the 45 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "Single-direction means exactly that: thrust on 51109 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The C0a of 69 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "The Ca 27.9/C0a 69 kN ratings and 3.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51109; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51109?",
        "a": "51109 is a single-direction thrust ball bearing to ISO 104: 45 mm shaft-washer bore, 65 mm outside diameter, 14 mm stack height (1.772 x 2.559 x 0.551 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 27.9 kN, C0a 69 kN and a 3.1 kN fatigue load limit Pu; the grease limiting speed is 3,200 r/min and the oil rating 4,600 r/min; mass about 148 g."
      },
      {
        "q": "How is the 51109 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 09 encodes the 45 mm bore (bore code x 5). The 65 mm OD and 14 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51109 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51109?",
        "a": "At the 3,200 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51109?",
        "a": "The 45/65/14 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 27.9 kN / C0a 69 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51109-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51109"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51209",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51209",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 45,
    "D_mm": 73,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 47.5,
    "static_load_kN": 105,
    "fatigue_load_limit_kN": 4.75,
    "limiting_speed_rpm": 2600,
    "max_rpm": 2600,
    "speed_oil_rpm": 3700,
    "weight_g": 317,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51209 is an NTN single-direction thrust ball bearing of the medium-section 51200 thrust family: 45 mm bore, 73 mm outside diameter, 20 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. Decoding 51209: 512 is the dimension series (medium-section 51200 thrust family), with 09 encodes the 45 mm bore (bore code x 5). Flat-seat washers make the bearing tolerant of simple housings but demand square faces: the whole 47.5 kN rating assumes the load arrives truly axial. Against a thrust roller bearing of the same 45 mm bore, this bearing is cheaper, quieter and happier at speed, but carries far less load per mm of section. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "conveyor vertical-drive thrust positions",
      "vertical motor and pump thrust shoes",
      "machine-tool tailstock and steady-rest screws",
      "medium crane hook blocks and slewing jibs"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 45 mm size together from unpacking to assembly.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 45 mm bore.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 47.5 kN never saves a bearing that is running too lightly loaded at 2,600 r/min.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 47.5 kN never saves a bearing that is running too lightly loaded at 2,600 r/min.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51209 stack height of 20 mm and washer set differ from the double-direction execution.",
      "The Ca 47.5/C0a 105 kN ratings and 4.75 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51209; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51209?",
        "a": "51209 is a single-direction thrust ball bearing to ISO 104: 45 mm shaft-washer bore, 73 mm outside diameter, 20 mm stack height (1.772 x 2.874 x 0.787 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 47.5 kN, C0a 105 kN and a 4.75 kN fatigue load limit Pu; the grease limiting speed is 2,600 r/min and the oil rating 3,700 r/min; mass about 317 g."
      },
      {
        "q": "How is the 51209 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 09 encodes the 45 mm bore (bore code x 5). The 73 mm OD and 20 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51209 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51209?",
        "a": "At the 2,600 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51209?",
        "a": "The 45/73/20 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 47.5 kN / C0a 105 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51209-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×73×20 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51209"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51309",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51309",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 45,
    "D_mm": 85,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 80,
    "static_load_kN": 163,
    "fatigue_load_limit_kN": 7.35,
    "limiting_speed_rpm": 2000,
    "max_rpm": 2000,
    "speed_oil_rpm": 2900,
    "weight_g": 684,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51309 belongs to the heavy-section 51300 thrust family of single-direction thrust ball bearings: 45 / 85 / 28 mm (shaft bore / OD / height). Two fields make up the code — 513 is the dimension series (heavy-section 51300 thrust family) and 09 encodes the 45 mm bore (bore code x 5). The static margin, C0a 163 kN against Ca 80 kN, is what carries slow oscillating or shock thrust without permanent raceway dents. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 51309 cannot. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "press and punch-machine thrust seats",
      "conveyor vertical-drive thrust positions",
      "vertical motor and pump thrust shoes",
      "machine-tool tailstock and steady-rest screws"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 45 mm size together from unpacking to assembly.",
      "The 513 heavy section buys capacity with a larger 85 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51309 has no radial capacity at all.",
      "Swapping the shaft and housing washers is an easy assembly error on the 45 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "Shock thrust above C0a 163 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The Ca 80/C0a 163 kN ratings and 7.35 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51309; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51309?",
        "a": "51309 is a single-direction thrust ball bearing to ISO 104: 45 mm shaft-washer bore, 85 mm outside diameter, 28 mm stack height (1.772 x 3.346 x 1.102 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 80 kN, C0a 163 kN and a 7.35 kN fatigue load limit Pu; the grease limiting speed is 2,000 r/min and the oil rating 2,900 r/min; mass about 684 g."
      },
      {
        "q": "How is the 51309 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 09 encodes the 45 mm bore (bore code x 5). The 85 mm OD and 28 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51309 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51309?",
        "a": "At the 2,000 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51309?",
        "a": "The 45/85/28 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 80 kN / C0a 163 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51309-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51309"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51409",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51409",
    "series": "51400-series",
    "type": "thrust_ball",
    "d_mm": 45,
    "D_mm": 100,
    "B_mm": 39,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 130,
    "static_load_kN": 242,
    "fatigue_load_limit_kN": 10.9,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 2200,
    "weight_g": 1430,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 45 x 100 x 39 mm, NTN 51409 sits in the extra-heavy 51400 thrust family of the single-direction thrust programme. NTN builds the number from 514 is the dimension series (extra-heavy 51400 thrust family); 09 encodes the 45 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 130 kN against C0a 242 kN — a static/dynamic ratio of 1.86 that is the signature of a thrust raceway. Size selection ends with the minimum-load check: at the 1,600 r/min class speed, the balls need a defined axial preload to keep rolling instead of skidding. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "medium crane hook blocks and slewing jibs",
      "extruder and mixer thrust housings",
      "winch and capstan vertical shafts",
      "press and punch-machine thrust seats"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 45 mm size together from unpacking to assembly.",
      "The 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "The C0a of 242 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Swapping the shaft and housing washers is an easy assembly error on the 45 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "The Ca 130/C0a 242 kN ratings and 10.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51409; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51409?",
        "a": "51409 is a single-direction thrust ball bearing to ISO 104: 45 mm shaft-washer bore, 100 mm outside diameter, 39 mm stack height (1.772 x 3.937 x 1.535 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 130 kN, C0a 242 kN and a 10.9 kN fatigue load limit Pu; the grease limiting speed is 1,600 r/min and the oil rating 2,200 r/min; mass about 1430 g."
      },
      {
        "q": "How is the 51409 designation structured?",
        "a": "514 is the dimension series (extra-heavy 51400 thrust family); 09 encodes the 45 mm bore (bore code x 5). The 100 mm OD and 39 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51409 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51409?",
        "a": "At the 1,600 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51409?",
        "a": "The 45/100/39 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 130 kN / C0a 242 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51409-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51409"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51110",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51110",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 50,
    "D_mm": 70,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 28.8,
    "static_load_kN": 75.5,
    "fatigue_load_limit_kN": 3.4,
    "limiting_speed_rpm": 3100,
    "max_rpm": 3100,
    "speed_oil_rpm": 4500,
    "weight_g": 161,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the light-section 51100 thrust family, 51110 measures 50 mm through the shaft washer, 70 mm over the outside and 14 mm in assembled height. Two fields make up the code — 511 is the dimension series (light-section 51100 thrust family) and 10 encodes the 50 mm bore (bore code x 5). Because the contact points run at 90 deg to the shaft, none of the rating is available for radial load — not even incidentally. If the duty is high speed with light thrust, check the minimum axial load formula first; a too-large thrust ball bearing fails by skid long before its Ca of 28.8 kN is ever approached. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "press and punch-machine thrust seats",
      "conveyor vertical-drive thrust positions",
      "vertical motor and pump thrust shoes",
      "machine-tool tailstock and steady-rest screws"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 50 mm size together from unpacking to assembly.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 50 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51110 has no radial capacity at all.",
      "Single-direction means exactly that: thrust on 51110 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The Ca 28.8/C0a 75.5 kN ratings and 3.4 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51110; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51110?",
        "a": "51110 is a single-direction thrust ball bearing to ISO 104: 50 mm shaft-washer bore, 70 mm outside diameter, 14 mm stack height (1.969 x 2.756 x 0.551 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 28.8 kN, C0a 75.5 kN and a 3.4 kN fatigue load limit Pu; the grease limiting speed is 3,100 r/min and the oil rating 4,500 r/min; mass about 161 g."
      },
      {
        "q": "How is the 51110 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 10 encodes the 50 mm bore (bore code x 5). The 70 mm OD and 14 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51110 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51110?",
        "a": "At the 3,100 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51110?",
        "a": "The 50/70/14 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 28.8 kN / C0a 75.5 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51110-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51110"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51210",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51210",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 50,
    "D_mm": 78,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 48.5,
    "static_load_kN": 111,
    "fatigue_load_limit_kN": 5.05,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "speed_oil_rpm": 3400,
    "weight_g": 378,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51210 appears as a medium-section 51200 thrust family bearing with a 50 mm shaft washer, a 78 mm housing diameter and 22 mm of stack height. Reading the code: 512 is the dimension series (medium-section 51200 thrust family), and 10 encodes the 50 mm bore (bore code x 5). The washer section here is 14.0 mm of radial height, and the catalogue couples it with Ca 48.5 kN / C0a 111 kN. Selection starts from the load direction: if thrust ever reverses, plan a second thrust bearing (or a double-direction execution) rather than relying on the unloaded raceway. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "extruder and mixer thrust housings",
      "winch and capstan vertical shafts",
      "press and punch-machine thrust seats",
      "conveyor vertical-drive thrust positions"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 50 mm size together from unpacking to assembly.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 50 mm bore.",
      "Swapping the shaft and housing washers is an easy assembly error on the 50 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "Swapping the shaft and housing washers is an easy assembly error on the 50 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "The C0a of 111 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "The Ca 48.5/C0a 111 kN ratings and 5.05 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51210; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51210?",
        "a": "51210 is a single-direction thrust ball bearing to ISO 104: 50 mm shaft-washer bore, 78 mm outside diameter, 22 mm stack height (1.969 x 3.071 x 0.866 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 48.5 kN, C0a 111 kN and a 5.05 kN fatigue load limit Pu; the grease limiting speed is 2,400 r/min and the oil rating 3,400 r/min; mass about 378 g."
      },
      {
        "q": "How is the 51210 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 10 encodes the 50 mm bore (bore code x 5). The 78 mm OD and 22 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51210 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51210?",
        "a": "At the 2,400 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51210?",
        "a": "The 50/78/22 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 48.5 kN / C0a 111 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51210-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51210"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51310",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51310",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 50,
    "D_mm": 95,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 96.5,
    "static_load_kN": 202,
    "fatigue_load_limit_kN": 9.1,
    "limiting_speed_rpm": 1800,
    "max_rpm": 1800,
    "speed_oil_rpm": 2600,
    "weight_g": 951,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The heavy-section 51300 thrust family entry 51310 stacks a shaft washer, ball-and-cage set and housing washer into 31 mm of height over a 50 mm bore. The designation is 513 is the dimension series (heavy-section 51300 thrust family) plus 10 encodes the 50 mm bore (bore code x 5). With Ca 96.5 kN and C0a 202 kN, each mm of shaft bore carries about 1.93 kN of dynamic axial rating. Size selection ends with the minimum-load check: at the 1,800 r/min class speed, the balls need a defined axial preload to keep rolling instead of skidding. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "medium crane hook blocks and slewing jibs",
      "extruder and mixer thrust housings",
      "winch and capstan vertical shafts",
      "press and punch-machine thrust seats"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 50 mm size together from unpacking to assembly.",
      "The 513 heavy section buys capacity with a larger 95 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 96.5 kN never saves a bearing that is running too lightly loaded at 1,800 r/min.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "The Ca 96.5/C0a 202 kN ratings and 9.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51310; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51310?",
        "a": "51310 is a single-direction thrust ball bearing to ISO 104: 50 mm shaft-washer bore, 95 mm outside diameter, 31 mm stack height (1.969 x 3.74 x 1.22 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 96.5 kN, C0a 202 kN and a 9.1 kN fatigue load limit Pu; the grease limiting speed is 1,800 r/min and the oil rating 2,600 r/min; mass about 951 g."
      },
      {
        "q": "How is the 51310 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 10 encodes the 50 mm bore (bore code x 5). The 95 mm OD and 31 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51310 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51310?",
        "a": "At the 1,800 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51310?",
        "a": "The 50/95/31 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 96.5 kN / C0a 202 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51310-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×95×31 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51310"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51410A",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51410A",
    "series": "51400-series",
    "type": "thrust_ball",
    "d_mm": 50,
    "D_mm": 110,
    "B_mm": 43,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 148,
    "static_load_kN": 283,
    "fatigue_load_limit_kN": 12.8,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 2000,
    "weight_g": 1900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51410A is an NTN single-direction thrust ball bearing of the extra-heavy 51400 thrust family: 50 mm bore, 110 mm outside diameter, 43 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. The designation is 514 is the dimension series (extra-heavy 51400 thrust family) plus 10 encodes the 50 mm bore (bore code x 5); the trailing A marks an internal-design revision of this dimension. With Ca 148 kN and C0a 283 kN, each mm of shaft bore carries about 2.96 kN of dynamic axial rating. Against a thrust roller bearing of the same 50 mm bore, this bearing is cheaper, quieter and happier at speed, but carries far less load per mm of section. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "vertical motor and pump thrust shoes",
      "machine-tool tailstock and steady-rest screws",
      "medium crane hook blocks and slewing jibs",
      "extruder and mixer thrust housings"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 50 mm size together from unpacking to assembly.",
      "The 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.",
      "The C0a of 283 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Single-direction means exactly that: thrust on 51410A in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "The Ca 148/C0a 283 kN ratings and 12.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51410A; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51410A?",
        "a": "51410A is a single-direction thrust ball bearing to ISO 104: 50 mm shaft-washer bore, 110 mm outside diameter, 43 mm stack height (1.969 x 4.331 x 1.693 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 148 kN, C0a 283 kN and a 12.8 kN fatigue load limit Pu; the grease limiting speed is 1,400 r/min and the oil rating 2,000 r/min; mass about 1900 g."
      },
      {
        "q": "How is the 51410A designation structured?",
        "a": "514 is the dimension series (extra-heavy 51400 thrust family); 10 encodes the 50 mm bore (bore code x 5); the trailing A marks an internal-design revision of this dimension. The 110 mm OD and 43 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51410A carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51410A?",
        "a": "At the 1,400 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51410A?",
        "a": "The 50/110/43 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 148 kN / C0a 283 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51410A",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51410a",
      "51410A"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51111",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51111",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 55,
    "D_mm": 78,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 35,
    "static_load_kN": 93,
    "fatigue_load_limit_kN": 4.2,
    "limiting_speed_rpm": 2800,
    "max_rpm": 2800,
    "speed_oil_rpm": 4000,
    "weight_g": 226,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51111 is an NTN single-direction thrust ball bearing of the light-section 51100 thrust family: 55 mm bore, 78 mm outside diameter, 16 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. Decoding 51111: 511 is the dimension series (light-section 51100 thrust family), with 11 encodes the 55 mm bore (bore code x 5). On speed, the grease limiting speed is 2,800 r/min and the oil rating 4,000 r/min. Size selection ends with the minimum-load check: at the 2,800 r/min class speed, the balls need a defined axial preload to keep rolling instead of skidding. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 78 mm OD already tilts the raceway and concentrates the 93 kN static capacity on a few balls. ",
    "applications": [
      "vertical motor and pump thrust shoes",
      "machine-tool tailstock and steady-rest screws",
      "medium crane hook blocks and slewing jibs",
      "extruder and mixer thrust housings"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 55 mm size together from unpacking to assembly.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 55 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 35 kN never saves a bearing that is running too lightly loaded at 2,800 r/min.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "The Ca 35/C0a 93 kN ratings and 4.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51111; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51111?",
        "a": "51111 is a single-direction thrust ball bearing to ISO 104: 55 mm shaft-washer bore, 78 mm outside diameter, 16 mm stack height (2.165 x 3.071 x 0.63 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 35 kN, C0a 93 kN and a 4.2 kN fatigue load limit Pu; the grease limiting speed is 2,800 r/min and the oil rating 4,000 r/min; mass about 226 g."
      },
      {
        "q": "How is the 51111 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 11 encodes the 55 mm bore (bore code x 5). The 78 mm OD and 16 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51111 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51111?",
        "a": "At the 2,800 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51111?",
        "a": "The 55/78/16 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 35 kN / C0a 93 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51111-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×78×16 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51111"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51211",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51211",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 55,
    "D_mm": 90,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 69.5,
    "static_load_kN": 159,
    "fatigue_load_limit_kN": 7.15,
    "limiting_speed_rpm": 2100,
    "max_rpm": 2100,
    "speed_oil_rpm": 3000,
    "weight_g": 608,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51211 belongs to the medium-section 51200 thrust family of single-direction thrust ball bearings: 55 / 90 / 25 mm (shaft bore / OD / height). Two fields make up the code — 512 is the dimension series (medium-section 51200 thrust family) and 11 encodes the 55 mm bore (bore code x 5). The ball-and-cage set is separable from both washers, which is why the mounting order (shaft washer first, then cage, then housing washer) matters. Choose the medium-section 51200 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. The shaft washer (bore 55 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "press and punch-machine thrust seats",
      "conveyor vertical-drive thrust positions",
      "vertical motor and pump thrust shoes",
      "machine-tool tailstock and steady-rest screws"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 55 mm size together from unpacking to assembly.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 55 mm bore.",
      "The C0a of 159 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51211 has no radial capacity at all.",
      "The Ca 69.5/C0a 159 kN ratings and 7.15 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51211; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51211?",
        "a": "51211 is a single-direction thrust ball bearing to ISO 104: 55 mm shaft-washer bore, 90 mm outside diameter, 25 mm stack height (2.165 x 3.543 x 0.984 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 69.5 kN, C0a 159 kN and a 7.15 kN fatigue load limit Pu; the grease limiting speed is 2,100 r/min and the oil rating 3,000 r/min; mass about 608 g."
      },
      {
        "q": "How is the 51211 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 11 encodes the 55 mm bore (bore code x 5). The 90 mm OD and 25 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51211 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51211?",
        "a": "At the 2,100 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51211?",
        "a": "The 55/90/25 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 69.5 kN / C0a 159 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51211-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×90×25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51211"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51311",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51311",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 55,
    "D_mm": 105,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 119,
    "static_load_kN": 246,
    "fatigue_load_limit_kN": 11.1,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 2300,
    "weight_g": 1290,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 55 x 105 x 35 mm, NTN 51311 sits in the heavy-section 51300 thrust family of the single-direction thrust programme. Reading the code: 513 is the dimension series (heavy-section 51300 thrust family), and 11 encodes the 55 mm bore (bore code x 5). Because the contact points run at 90 deg to the shaft, none of the rating is available for radial load — not even incidentally. Within the thrust-ball plan, 511 is the light section and 514 the heaviest for a given bore; moving up a series raises the C0a from 246 kN class figures at the cost of OD and height. The shaft washer (bore 55 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "winch and capstan vertical shafts",
      "press and punch-machine thrust seats",
      "conveyor vertical-drive thrust positions",
      "vertical motor and pump thrust shoes"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 55 mm size together from unpacking to assembly.",
      "The 513 heavy section buys capacity with a larger 105 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "The C0a of 246 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Single-direction means exactly that: thrust on 51311 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The Ca 119/C0a 246 kN ratings and 11.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51311; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51311?",
        "a": "51311 is a single-direction thrust ball bearing to ISO 104: 55 mm shaft-washer bore, 105 mm outside diameter, 35 mm stack height (2.165 x 4.134 x 1.378 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 119 kN, C0a 246 kN and a 11.1 kN fatigue load limit Pu; the grease limiting speed is 1,600 r/min and the oil rating 2,300 r/min; mass about 1290 g."
      },
      {
        "q": "How is the 51311 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 11 encodes the 55 mm bore (bore code x 5). The 105 mm OD and 35 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51311 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51311?",
        "a": "At the 1,600 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51311?",
        "a": "The 55/105/35 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 119 kN / C0a 246 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51311-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×105×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51311"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51411",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51411",
    "series": "51400-series",
    "type": "thrust_ball",
    "d_mm": 55,
    "D_mm": 120,
    "B_mm": 48,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 178,
    "static_load_kN": 360,
    "fatigue_load_limit_kN": 16.2,
    "limiting_speed_rpm": 1300,
    "max_rpm": 1300,
    "speed_oil_rpm": 1800,
    "weight_g": 2520,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the extra-heavy 51400 thrust family, 51411 measures 55 mm through the shaft washer, 120 mm over the outside and 48 mm in assembled height. Decoding 51411: 514 is the dimension series (extra-heavy 51400 thrust family), with 11 encodes the 55 mm bore (bore code x 5). The washer section here is 32.5 mm of radial height, and the catalogue couples it with Ca 178 kN / C0a 360 kN. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 51411 cannot. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "machine-tool tailstock and steady-rest screws",
      "medium crane hook blocks and slewing jibs",
      "extruder and mixer thrust housings",
      "winch and capstan vertical shafts"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "In this size class the frequent miss is washer identification: keep the catalogued shaft/housing washer pairing of the 55 mm size together from unpacking to assembly.",
      "The 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.",
      "Shock thrust above C0a 360 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "The C0a of 360 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "The Ca 178/C0a 360 kN ratings and 16.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51411; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51411?",
        "a": "51411 is a single-direction thrust ball bearing to ISO 104: 55 mm shaft-washer bore, 120 mm outside diameter, 48 mm stack height (2.165 x 4.724 x 1.89 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 178 kN, C0a 360 kN and a 16.2 kN fatigue load limit Pu; the grease limiting speed is 1,300 r/min and the oil rating 1,800 r/min; mass about 2520 g."
      },
      {
        "q": "How is the 51411 designation structured?",
        "a": "514 is the dimension series (extra-heavy 51400 thrust family); 11 encodes the 55 mm bore (bore code x 5). The 120 mm OD and 48 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51411 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51411?",
        "a": "At the 1,300 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51411?",
        "a": "The 55/120/48 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 178 kN / C0a 360 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51411-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51411"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51112",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51112",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 60,
    "D_mm": 85,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 41.5,
    "static_load_kN": 113,
    "fatigue_load_limit_kN": 5.1,
    "limiting_speed_rpm": 2600,
    "max_rpm": 2600,
    "speed_oil_rpm": 3700,
    "weight_g": 296,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51112 appears as a light-section 51100 thrust family bearing with a 60 mm shaft washer, a 85 mm housing diameter and 17 mm of stack height. NTN builds the number from 511 is the dimension series (light-section 51100 thrust family); 12 encodes the 60 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 41.5 kN against C0a 113 kN — a static/dynamic ratio of 2.72 that is the signature of a thrust raceway. Within the thrust-ball plan, 511 is the light section and 514 the heaviest for a given bore; moving up a series raises the C0a from 113 kN class figures at the cost of OD and height. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "rolling-mill screwdown and adjustment screws",
      "heavy press and forging-machine thrust seats",
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "At 60 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 60 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "The 2,600 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "Swapping the shaft and housing washers is an easy assembly error on the 60 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "Swapping the shaft and housing washers is an easy assembly error on the 60 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "The Ca 41.5/C0a 113 kN ratings and 5.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51112; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51112?",
        "a": "51112 is a single-direction thrust ball bearing to ISO 104: 60 mm shaft-washer bore, 85 mm outside diameter, 17 mm stack height (2.362 x 3.346 x 0.669 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 41.5 kN, C0a 113 kN and a 5.1 kN fatigue load limit Pu; the grease limiting speed is 2,600 r/min and the oil rating 3,700 r/min; mass about 296 g."
      },
      {
        "q": "How is the 51112 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 12 encodes the 60 mm bore (bore code x 5). The 85 mm OD and 17 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51112 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51112?",
        "a": "At the 2,600 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51112?",
        "a": "The 60/85/17 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 41.5 kN / C0a 113 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51112-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51112"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51212",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51212",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 60,
    "D_mm": 95,
    "B_mm": 26,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 73.5,
    "static_load_kN": 179,
    "fatigue_load_limit_kN": 8.05,
    "limiting_speed_rpm": 2000,
    "max_rpm": 2000,
    "speed_oil_rpm": 2800,
    "weight_g": 676,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The medium-section 51200 thrust family entry 51212 stacks a shaft washer, ball-and-cage set and housing washer into 26 mm of height over a 60 mm bore. Decoding 51212: 512 is the dimension series (medium-section 51200 thrust family), with 12 encodes the 60 mm bore (bore code x 5). Catalogue mass is about 676 g for the full washer-and-cage stack. The 60/95/26 envelope follows ISO 104, so dimensional interchange holds between makers — raceway osculation and ratings do not automatically follow. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "vertical water-pump and turbine thrust blocks",
      "large crane hook and swivel assemblies",
      "rolling-mill screwdown and adjustment screws",
      "heavy press and forging-machine thrust seats"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "At 60 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 60 mm bore.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "The C0a of 179 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "The 2,000 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "The Ca 73.5/C0a 179 kN ratings and 8.05 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51212; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51212?",
        "a": "51212 is a single-direction thrust ball bearing to ISO 104: 60 mm shaft-washer bore, 95 mm outside diameter, 26 mm stack height (2.362 x 3.74 x 1.024 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 73.5 kN, C0a 179 kN and a 8.05 kN fatigue load limit Pu; the grease limiting speed is 2,000 r/min and the oil rating 2,800 r/min; mass about 676 g."
      },
      {
        "q": "How is the 51212 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 12 encodes the 60 mm bore (bore code x 5). The 95 mm OD and 26 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51212 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51212?",
        "a": "At the 2,000 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51212?",
        "a": "The 60/95/26 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 73.5 kN / C0a 179 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51212-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×95×26 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51212"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51312",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51312",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 123,
    "static_load_kN": 267,
    "fatigue_load_limit_kN": 12,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 2300,
    "weight_g": 1370,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51312 is the 60 mm member of NTN's heavy-section 51300 thrust family: 110 mm across the washers, 35 mm tall. Two fields make up the code — 513 is the dimension series (heavy-section 51300 thrust family) and 12 encodes the 60 mm bore (bore code x 5). On speed, the grease limiting speed is 1,600 r/min and the oil rating 2,300 r/min. Selection starts from the load direction: if thrust ever reverses, plan a second thrust bearing (or a double-direction execution) rather than relying on the unloaded raceway. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks",
      "large crane hook and swivel assemblies",
      "rolling-mill screwdown and adjustment screws"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "At 60 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 513 heavy section buys capacity with a larger 110 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "The Ca 123/C0a 267 kN ratings and 12 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51312; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51312?",
        "a": "51312 is a single-direction thrust ball bearing to ISO 104: 60 mm shaft-washer bore, 110 mm outside diameter, 35 mm stack height (2.362 x 4.331 x 1.378 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 123 kN, C0a 267 kN and a 12 kN fatigue load limit Pu; the grease limiting speed is 1,600 r/min and the oil rating 2,300 r/min; mass about 1370 g."
      },
      {
        "q": "How is the 51312 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 12 encodes the 60 mm bore (bore code x 5). The 110 mm OD and 35 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51312 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51312?",
        "a": "At the 1,600 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51312?",
        "a": "The 60/110/35 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 123 kN / C0a 267 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51312-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51312"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51412",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51412",
    "series": "51400-series",
    "type": "thrust_ball",
    "d_mm": 60,
    "D_mm": 130,
    "B_mm": 51,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 214,
    "static_load_kN": 435,
    "fatigue_load_limit_kN": 19.7,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1700,
    "weight_g": 3120,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51412 is an NTN single-direction thrust ball bearing of the extra-heavy 51400 thrust family: 60 mm bore, 130 mm outside diameter, 51 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. NTN builds the number from 514 is the dimension series (extra-heavy 51400 thrust family); 12 encodes the 60 mm bore (bore code x 5). The ball-and-cage set is separable from both washers, which is why the mounting order (shaft washer first, then cage, then housing washer) matters. For a 60 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot. ",
    "applications": [
      "heavy press and forging-machine thrust seats",
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "At 60 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.",
      "Single-direction means exactly that: thrust on 51412 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The 1,200 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51412 has no radial capacity at all.",
      "The Ca 214/C0a 435 kN ratings and 19.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51412; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51412?",
        "a": "51412 is a single-direction thrust ball bearing to ISO 104: 60 mm shaft-washer bore, 130 mm outside diameter, 51 mm stack height (2.362 x 5.118 x 2.008 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 214 kN, C0a 435 kN and a 19.7 kN fatigue load limit Pu; the grease limiting speed is 1,200 r/min and the oil rating 1,700 r/min; mass about 3120 g."
      },
      {
        "q": "How is the 51412 designation structured?",
        "a": "514 is the dimension series (extra-heavy 51400 thrust family); 12 encodes the 60 mm bore (bore code x 5). The 130 mm OD and 51 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51412 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51412?",
        "a": "At the 1,200 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51412?",
        "a": "The 60/130/51 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 214 kN / C0a 435 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51412-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51412"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51113",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51113",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 65,
    "D_mm": 90,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 41.5,
    "static_load_kN": 117,
    "fatigue_load_limit_kN": 5.3,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "speed_oil_rpm": 3500,
    "weight_g": 338,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51113 belongs to the light-section 51100 thrust family of single-direction thrust ball bearings: 65 / 90 / 18 mm (shaft bore / OD / height). The designation is 511 is the dimension series (light-section 51100 thrust family) plus 13 encodes the 65 mm bore (bore code x 5). Flat-seat washers make the bearing tolerant of simple housings but demand square faces: the whole 41.5 kN rating assumes the load arrives truly axial. Selection starts from the load direction: if thrust ever reverses, plan a second thrust bearing (or a double-direction execution) rather than relying on the unloaded raceway. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot. ",
    "applications": [
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "At 65 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 65 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51113 stack height of 18 mm and washer set differ from the double-direction execution.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51113 stack height of 18 mm and washer set differ from the double-direction execution.",
      "The Ca 41.5/C0a 117 kN ratings and 5.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51113; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51113?",
        "a": "51113 is a single-direction thrust ball bearing to ISO 104: 65 mm shaft-washer bore, 90 mm outside diameter, 18 mm stack height (2.559 x 3.543 x 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 41.5 kN, C0a 117 kN and a 5.3 kN fatigue load limit Pu; the grease limiting speed is 2,400 r/min and the oil rating 3,500 r/min; mass about 338 g."
      },
      {
        "q": "How is the 51113 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 13 encodes the 65 mm bore (bore code x 5). The 90 mm OD and 18 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51113 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51113?",
        "a": "At the 2,400 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51113?",
        "a": "The 65/90/18 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 41.5 kN / C0a 117 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51113-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×90×18 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51113"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51213",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51213",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 65,
    "D_mm": 100,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 75,
    "static_load_kN": 189,
    "fatigue_load_limit_kN": 8.5,
    "limiting_speed_rpm": 1900,
    "max_rpm": 1900,
    "speed_oil_rpm": 2700,
    "weight_g": 767,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 65 x 100 x 27 mm, NTN 51213 sits in the medium-section 51200 thrust family of the single-direction thrust programme. NTN builds the number from 512 is the dimension series (medium-section 51200 thrust family); 13 encodes the 65 mm bore (bore code x 5). With Ca 75 kN and C0a 189 kN, each mm of shaft bore carries about 1.15 kN of dynamic axial rating. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 51213 cannot. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "rolling-mill screwdown and adjustment screws",
      "heavy press and forging-machine thrust seats",
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "At 65 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 65 mm bore.",
      "Shock thrust above C0a 189 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "The Ca 75/C0a 189 kN ratings and 8.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51213; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51213?",
        "a": "51213 is a single-direction thrust ball bearing to ISO 104: 65 mm shaft-washer bore, 100 mm outside diameter, 27 mm stack height (2.559 x 3.937 x 1.063 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 75 kN, C0a 189 kN and a 8.5 kN fatigue load limit Pu; the grease limiting speed is 1,900 r/min and the oil rating 2,700 r/min; mass about 767 g."
      },
      {
        "q": "How is the 51213 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 13 encodes the 65 mm bore (bore code x 5). The 100 mm OD and 27 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51213 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51213?",
        "a": "At the 1,900 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51213?",
        "a": "The 65/100/27 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 75 kN / C0a 189 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51213-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×100×27 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51213"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51313",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51313",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 65,
    "D_mm": 115,
    "B_mm": 36,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 128,
    "static_load_kN": 287,
    "fatigue_load_limit_kN": 13,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 2200,
    "weight_g": 1510,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the heavy-section 51300 thrust family, 51313 measures 65 mm through the shaft washer, 115 mm over the outside and 36 mm in assembled height. Decoding 51313: 513 is the dimension series (heavy-section 51300 thrust family), with 13 encodes the 65 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 128 kN against C0a 287 kN — a static/dynamic ratio of 2.24 that is the signature of a thrust raceway. Choose the heavy-section 51300 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "large crane hook and swivel assemblies",
      "rolling-mill screwdown and adjustment screws",
      "heavy press and forging-machine thrust seats",
      "ship winch and capstan thrust shafts"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "At 65 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 513 heavy section buys capacity with a larger 115 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "The 1,500 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "Swapping the shaft and housing washers is an easy assembly error on the 65 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "The Ca 128/C0a 287 kN ratings and 13 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51313; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51313?",
        "a": "51313 is a single-direction thrust ball bearing to ISO 104: 65 mm shaft-washer bore, 115 mm outside diameter, 36 mm stack height (2.559 x 4.528 x 1.417 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 128 kN, C0a 287 kN and a 13 kN fatigue load limit Pu; the grease limiting speed is 1,500 r/min and the oil rating 2,200 r/min; mass about 1510 g."
      },
      {
        "q": "How is the 51313 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 13 encodes the 65 mm bore (bore code x 5). The 115 mm OD and 36 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51313 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51313?",
        "a": "At the 1,500 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51313?",
        "a": "The 65/115/36 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 128 kN / C0a 287 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51313-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×115×36 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51313"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51413",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51413",
    "series": "51400-series",
    "type": "thrust_ball",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 56,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 232,
    "static_load_kN": 495,
    "fatigue_load_limit_kN": 22,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1600,
    "weight_g": 3960,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51413 appears as a extra-heavy 51400 thrust family bearing with a 65 mm shaft washer, a 140 mm housing diameter and 56 mm of stack height. The designation is 514 is the dimension series (extra-heavy 51400 thrust family) plus 13 encodes the 65 mm bore (bore code x 5). Catalogue mass is about 3960 g for the full washer-and-cage stack. Against a thrust roller bearing of the same 65 mm bore, this bearing is cheaper, quieter and happier at speed, but carries far less load per mm of section. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks",
      "large crane hook and swivel assemblies"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "At 65 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 232 kN never saves a bearing that is running too lightly loaded at 1,100 r/min.",
      "Shock thrust above C0a 495 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The 1,100 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "The Ca 232/C0a 495 kN ratings and 22 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51413; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51413?",
        "a": "51413 is a single-direction thrust ball bearing to ISO 104: 65 mm shaft-washer bore, 140 mm outside diameter, 56 mm stack height (2.559 x 5.512 x 2.205 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 232 kN, C0a 495 kN and a 22 kN fatigue load limit Pu; the grease limiting speed is 1,100 r/min and the oil rating 1,600 r/min; mass about 3960 g."
      },
      {
        "q": "How is the 51413 designation structured?",
        "a": "514 is the dimension series (extra-heavy 51400 thrust family); 13 encodes the 65 mm bore (bore code x 5). The 140 mm OD and 56 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51413 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51413?",
        "a": "At the 1,100 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51413?",
        "a": "The 65/140/56 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 232 kN / C0a 495 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51413-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51413"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51114",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51114",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 70,
    "D_mm": 95,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 43,
    "static_load_kN": 127,
    "fatigue_load_limit_kN": 5.7,
    "limiting_speed_rpm": 2400,
    "max_rpm": 2400,
    "speed_oil_rpm": 3400,
    "weight_g": 356,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The light-section 51100 thrust family entry 51114 stacks a shaft washer, ball-and-cage set and housing washer into 18 mm of height over a 70 mm bore. Reading the code: 511 is the dimension series (light-section 51100 thrust family), and 14 encodes the 70 mm bore (bore code x 5). NTN prints 43 kN axial dynamic and 127 kN axial static for this size and a 5.7 kN fatigue load limit Pu. Choose the light-section 51100 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks",
      "large crane hook and swivel assemblies",
      "rolling-mill screwdown and adjustment screws"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "At 70 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 70 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51114 has no radial capacity at all.",
      "The C0a of 127 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "The Ca 43/C0a 127 kN ratings and 5.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51114; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51114?",
        "a": "51114 is a single-direction thrust ball bearing to ISO 104: 70 mm shaft-washer bore, 95 mm outside diameter, 18 mm stack height (2.756 x 3.74 x 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 43 kN, C0a 127 kN and a 5.7 kN fatigue load limit Pu; the grease limiting speed is 2,400 r/min and the oil rating 3,400 r/min; mass about 356 g."
      },
      {
        "q": "How is the 51114 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 14 encodes the 70 mm bore (bore code x 5). The 95 mm OD and 18 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51114 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51114?",
        "a": "At the 2,400 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51114?",
        "a": "The 70/95/18 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 43 kN / C0a 127 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51114-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51114"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51214",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51214",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 70,
    "D_mm": 105,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 76,
    "static_load_kN": 199,
    "fatigue_load_limit_kN": 8.95,
    "limiting_speed_rpm": 1800,
    "max_rpm": 1800,
    "speed_oil_rpm": 2600,
    "weight_g": 793,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51214 is the 70 mm member of NTN's medium-section 51200 thrust family: 105 mm across the washers, 27 mm tall. The designation is 512 is the dimension series (medium-section 51200 thrust family) plus 14 encodes the 70 mm bore (bore code x 5). Because the contact points run at 90 deg to the shaft, none of the rating is available for radial load — not even incidentally. For a 70 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 105 mm OD already tilts the raceway and concentrates the 199 kN static capacity on a few balls. ",
    "applications": [
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "At 70 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 70 mm bore.",
      "Single-direction means exactly that: thrust on 51214 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "Single-direction means exactly that: thrust on 51214 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The Ca 76/C0a 199 kN ratings and 8.95 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51214; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51214?",
        "a": "51214 is a single-direction thrust ball bearing to ISO 104: 70 mm shaft-washer bore, 105 mm outside diameter, 27 mm stack height (2.756 x 4.134 x 1.063 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 76 kN, C0a 199 kN and a 8.95 kN fatigue load limit Pu; the grease limiting speed is 1,800 r/min and the oil rating 2,600 r/min; mass about 793 g."
      },
      {
        "q": "How is the 51214 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 14 encodes the 70 mm bore (bore code x 5). The 105 mm OD and 27 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51214 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51214?",
        "a": "At the 1,800 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51214?",
        "a": "The 70/105/27 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 76 kN / C0a 199 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51214-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×105×27 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51214"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51314",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51314",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 70,
    "D_mm": 125,
    "B_mm": 40,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 148,
    "static_load_kN": 340,
    "fatigue_load_limit_kN": 15.3,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 2000,
    "weight_g": 2010,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51314 is an NTN single-direction thrust ball bearing of the heavy-section 51300 thrust family: 70 mm bore, 125 mm outside diameter, 40 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. NTN builds the number from 513 is the dimension series (heavy-section 51300 thrust family); 14 encodes the 70 mm bore (bore code x 5). Flat-seat washers make the bearing tolerant of simple housings but demand square faces: the whole 148 kN rating assumes the load arrives truly axial. The 70/125/40 envelope follows ISO 104, so dimensional interchange holds between makers — raceway osculation and ratings do not automatically follow. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 125 mm OD already tilts the raceway and concentrates the 340 kN static capacity on a few balls. ",
    "applications": [
      "heavy press and forging-machine thrust seats",
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "At 70 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 513 heavy section buys capacity with a larger 125 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51314 stack height of 40 mm and washer set differ from the double-direction execution.",
      "The 1,400 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51314 stack height of 40 mm and washer set differ from the double-direction execution.",
      "The Ca 148/C0a 340 kN ratings and 15.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51314; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51314?",
        "a": "51314 is a single-direction thrust ball bearing to ISO 104: 70 mm shaft-washer bore, 125 mm outside diameter, 40 mm stack height (2.756 x 4.921 x 1.575 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 148 kN, C0a 340 kN and a 15.3 kN fatigue load limit Pu; the grease limiting speed is 1,400 r/min and the oil rating 2,000 r/min; mass about 2010 g."
      },
      {
        "q": "How is the 51314 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 14 encodes the 70 mm bore (bore code x 5). The 125 mm OD and 40 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51314 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51314?",
        "a": "At the 1,400 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51314?",
        "a": "The 70/125/40 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 148 kN / C0a 340 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51314-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51314"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51414",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51414",
    "series": "51400-series",
    "type": "thrust_ball",
    "d_mm": 70,
    "D_mm": 150,
    "B_mm": 60,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 250,
    "static_load_kN": 555,
    "fatigue_load_limit_kN": 23.8,
    "limiting_speed_rpm": 1000,
    "max_rpm": 1000,
    "speed_oil_rpm": 1500,
    "weight_g": 4860,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51414 belongs to the extra-heavy 51400 thrust family of single-direction thrust ball bearings: 70 / 150 / 60 mm (shaft bore / OD / height). Reading the code: 514 is the dimension series (extra-heavy 51400 thrust family), and 14 encodes the 70 mm bore (bore code x 5). With Ca 250 kN and C0a 555 kN, each mm of shaft bore carries about 3.57 kN of dynamic axial rating. If the duty is high speed with light thrust, check the minimum axial load formula first; a too-large thrust ball bearing fails by skid long before its Ca of 250 kN is ever approached. The shaft washer (bore 70 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "vertical water-pump and turbine thrust blocks",
      "large crane hook and swivel assemblies",
      "rolling-mill screwdown and adjustment screws",
      "heavy press and forging-machine thrust seats"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "At 70 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51414 stack height of 60 mm and washer set differ from the double-direction execution.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "The Ca 250/C0a 555 kN ratings and 23.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51414; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51414?",
        "a": "51414 is a single-direction thrust ball bearing to ISO 104: 70 mm shaft-washer bore, 150 mm outside diameter, 60 mm stack height (2.756 x 5.906 x 2.362 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 250 kN, C0a 555 kN and a 23.8 kN fatigue load limit Pu; the grease limiting speed is 1,000 r/min and the oil rating 1,500 r/min; mass about 4860 g."
      },
      {
        "q": "How is the 51414 designation structured?",
        "a": "514 is the dimension series (extra-heavy 51400 thrust family); 14 encodes the 70 mm bore (bore code x 5). The 150 mm OD and 60 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51414 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51414?",
        "a": "At the 1,000 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51414?",
        "a": "The 70/150/60 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 250 kN / C0a 555 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51414-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51414"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51115",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51115",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 75,
    "D_mm": 100,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 44.5,
    "static_load_kN": 136,
    "fatigue_load_limit_kN": 6.15,
    "limiting_speed_rpm": 2200,
    "max_rpm": 2200,
    "speed_oil_rpm": 3200,
    "weight_g": 399,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 75 x 100 x 19 mm, NTN 51115 sits in the light-section 51100 thrust family of the single-direction thrust programme. Two fields make up the code — 511 is the dimension series (light-section 51100 thrust family) and 15 encodes the 75 mm bore (bore code x 5). At 19 mm of height the stack is compact for the 75 mm bore class, trading section height for the light-section load level. The 75/100/19 envelope follows ISO 104, so dimensional interchange holds between makers — raceway osculation and ratings do not automatically follow. The shaft washer (bore 75 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "large crane hook and swivel assemblies",
      "rolling-mill screwdown and adjustment screws",
      "heavy press and forging-machine thrust seats",
      "ship winch and capstan thrust shafts"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "At 75 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 75 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Swapping the shaft and housing washers is an easy assembly error on the 75 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 44.5 kN never saves a bearing that is running too lightly loaded at 2,200 r/min.",
      "The Ca 44.5/C0a 136 kN ratings and 6.15 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51115; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51115?",
        "a": "51115 is a single-direction thrust ball bearing to ISO 104: 75 mm shaft-washer bore, 100 mm outside diameter, 19 mm stack height (2.953 x 3.937 x 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 44.5 kN, C0a 136 kN and a 6.15 kN fatigue load limit Pu; the grease limiting speed is 2,200 r/min and the oil rating 3,200 r/min; mass about 399 g."
      },
      {
        "q": "How is the 51115 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 15 encodes the 75 mm bore (bore code x 5). The 100 mm OD and 19 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51115 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51115?",
        "a": "At the 2,200 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51115?",
        "a": "The 75/100/19 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 44.5 kN / C0a 136 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51115-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51115"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51215",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51215",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 75,
    "D_mm": 110,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 77.5,
    "static_load_kN": 209,
    "fatigue_load_limit_kN": 9.4,
    "limiting_speed_rpm": 1800,
    "max_rpm": 1800,
    "speed_oil_rpm": 2600,
    "weight_g": 874,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the medium-section 51200 thrust family, 51215 measures 75 mm through the shaft washer, 110 mm over the outside and 27 mm in assembled height. Reading the code: 512 is the dimension series (medium-section 51200 thrust family), and 15 encodes the 75 mm bore (bore code x 5). On speed, the grease limiting speed is 1,800 r/min and the oil rating 2,600 r/min. Against a thrust roller bearing of the same 75 mm bore, this bearing is cheaper, quieter and happier at speed, but carries far less load per mm of section. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks",
      "large crane hook and swivel assemblies",
      "rolling-mill screwdown and adjustment screws"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "At 75 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 75 mm bore.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 77.5 kN never saves a bearing that is running too lightly loaded at 1,800 r/min.",
      "The 1,800 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "The Ca 77.5/C0a 209 kN ratings and 9.4 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51215; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51215?",
        "a": "51215 is a single-direction thrust ball bearing to ISO 104: 75 mm shaft-washer bore, 110 mm outside diameter, 27 mm stack height (2.953 x 4.331 x 1.063 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 77.5 kN, C0a 209 kN and a 9.4 kN fatigue load limit Pu; the grease limiting speed is 1,800 r/min and the oil rating 2,600 r/min; mass about 874 g."
      },
      {
        "q": "How is the 51215 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 15 encodes the 75 mm bore (bore code x 5). The 110 mm OD and 27 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51215 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51215?",
        "a": "At the 1,800 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51215?",
        "a": "The 75/110/27 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 77.5 kN / C0a 209 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51215-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 75×110×27 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51215"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51315",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51315",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 75,
    "D_mm": 135,
    "B_mm": 44,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 171,
    "static_load_kN": 395,
    "fatigue_load_limit_kN": 17.4,
    "limiting_speed_rpm": 1300,
    "max_rpm": 1300,
    "speed_oil_rpm": 1800,
    "weight_g": 2610,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51315 appears as a heavy-section 51300 thrust family bearing with a 75 mm shaft washer, a 135 mm housing diameter and 44 mm of stack height. The designation is 513 is the dimension series (heavy-section 51300 thrust family) plus 15 encodes the 75 mm bore (bore code x 5). NTN prints 171 kN axial dynamic and 395 kN axial static for this size and a 17.4 kN fatigue load limit Pu. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 51315 cannot. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks",
      "large crane hook and swivel assemblies"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "At 75 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 513 heavy section buys capacity with a larger 135 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51315 has no radial capacity at all.",
      "Shock thrust above C0a 395 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "The Ca 171/C0a 395 kN ratings and 17.4 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51315; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51315?",
        "a": "51315 is a single-direction thrust ball bearing to ISO 104: 75 mm shaft-washer bore, 135 mm outside diameter, 44 mm stack height (2.953 x 5.315 x 1.732 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 171 kN, C0a 395 kN and a 17.4 kN fatigue load limit Pu; the grease limiting speed is 1,300 r/min and the oil rating 1,800 r/min; mass about 2610 g."
      },
      {
        "q": "How is the 51315 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 15 encodes the 75 mm bore (bore code x 5). The 135 mm OD and 44 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51315 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51315?",
        "a": "At the 1,300 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51315?",
        "a": "The 75/135/44 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 171 kN / C0a 395 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51315-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51315"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51415",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51415",
    "series": "51400-series",
    "type": "thrust_ball",
    "d_mm": 75,
    "D_mm": 160,
    "B_mm": 65,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 269,
    "static_load_kN": 615,
    "fatigue_load_limit_kN": 25.6,
    "limiting_speed_rpm": 940,
    "max_rpm": 940,
    "speed_oil_rpm": 1400,
    "weight_g": 5970,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The extra-heavy 51400 thrust family entry 51415 stacks a shaft washer, ball-and-cage set and housing washer into 65 mm of height over a 75 mm bore. Two fields make up the code — 514 is the dimension series (extra-heavy 51400 thrust family) and 15 encodes the 75 mm bore (bore code x 5). Because the contact points run at 90 deg to the shaft, none of the rating is available for radial load — not even incidentally. Size selection ends with the minimum-load check: at the 940 r/min class speed, the balls need a defined axial preload to keep rolling instead of skidding. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "rolling-mill screwdown and adjustment screws",
      "heavy press and forging-machine thrust seats",
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "At 75 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "Single-direction means exactly that: thrust on 51415 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Single-direction means exactly that: thrust on 51415 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The Ca 269/C0a 615 kN ratings and 25.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51415; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51415?",
        "a": "51415 is a single-direction thrust ball bearing to ISO 104: 75 mm shaft-washer bore, 160 mm outside diameter, 65 mm stack height (2.953 x 6.299 x 2.559 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 269 kN, C0a 615 kN and a 25.6 kN fatigue load limit Pu; the grease limiting speed is 940 r/min and the oil rating 1,400 r/min; mass about 5970 g."
      },
      {
        "q": "How is the 51415 designation structured?",
        "a": "514 is the dimension series (extra-heavy 51400 thrust family); 15 encodes the 75 mm bore (bore code x 5). The 160 mm OD and 65 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51415 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51415?",
        "a": "At the 940 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51415?",
        "a": "The 75/160/65 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 269 kN / C0a 615 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51415-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51415"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51116",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51116",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 80,
    "D_mm": 105,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 44.5,
    "static_load_kN": 141,
    "fatigue_load_limit_kN": 6.35,
    "limiting_speed_rpm": 2200,
    "max_rpm": 2200,
    "speed_oil_rpm": 3100,
    "weight_g": 422,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51116 is the 80 mm member of NTN's light-section 51100 thrust family: 105 mm across the washers, 19 mm tall. Decoding 51116: 511 is the dimension series (light-section 51100 thrust family), with 16 encodes the 80 mm bore (bore code x 5). The static margin, C0a 141 kN against Ca 44.5 kN, is what carries slow oscillating or shock thrust without permanent raceway dents. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 51116 cannot. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "heavy press and forging-machine thrust seats",
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "At 80 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 80 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "The C0a of 141 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "Shock thrust above C0a 141 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The Ca 44.5/C0a 141 kN ratings and 6.35 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51116; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51116?",
        "a": "51116 is a single-direction thrust ball bearing to ISO 104: 80 mm shaft-washer bore, 105 mm outside diameter, 19 mm stack height (3.15 x 4.134 x 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 44.5 kN, C0a 141 kN and a 6.35 kN fatigue load limit Pu; the grease limiting speed is 2,200 r/min and the oil rating 3,100 r/min; mass about 422 g."
      },
      {
        "q": "How is the 51116 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 16 encodes the 80 mm bore (bore code x 5). The 105 mm OD and 19 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51116 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51116?",
        "a": "At the 2,200 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51116?",
        "a": "The 80/105/19 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 44.5 kN / C0a 141 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51116-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51116"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51216",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51216",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 80,
    "D_mm": 115,
    "B_mm": 28,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 78.5,
    "static_load_kN": 218,
    "fatigue_load_limit_kN": 9.85,
    "limiting_speed_rpm": 1700,
    "max_rpm": 1700,
    "speed_oil_rpm": 2400,
    "weight_g": 916,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51216 is an NTN single-direction thrust ball bearing of the medium-section 51200 thrust family: 80 mm bore, 115 mm outside diameter, 28 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. Two fields make up the code — 512 is the dimension series (medium-section 51200 thrust family) and 16 encodes the 80 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 78.5 kN against C0a 218 kN — a static/dynamic ratio of 2.78 that is the signature of a thrust raceway. If the duty is high speed with light thrust, check the minimum axial load formula first; a too-large thrust ball bearing fails by skid long before its Ca of 78.5 kN is ever approached. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot. ",
    "applications": [
      "large crane hook and swivel assemblies",
      "rolling-mill screwdown and adjustment screws",
      "heavy press and forging-machine thrust seats",
      "ship winch and capstan thrust shafts"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "At 80 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 80 mm bore.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Shock thrust above C0a 218 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Swapping the shaft and housing washers is an easy assembly error on the 80 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "The Ca 78.5/C0a 218 kN ratings and 9.85 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51216; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51216?",
        "a": "51216 is a single-direction thrust ball bearing to ISO 104: 80 mm shaft-washer bore, 115 mm outside diameter, 28 mm stack height (3.15 x 4.528 x 1.102 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 78.5 kN, C0a 218 kN and a 9.85 kN fatigue load limit Pu; the grease limiting speed is 1,700 r/min and the oil rating 2,400 r/min; mass about 916 g."
      },
      {
        "q": "How is the 51216 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 16 encodes the 80 mm bore (bore code x 5). The 115 mm OD and 28 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51216 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51216?",
        "a": "At the 1,700 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51216?",
        "a": "The 80/115/28 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 78.5 kN / C0a 218 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51216-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51216"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51316",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51316",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 80,
    "D_mm": 140,
    "B_mm": 44,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 176,
    "static_load_kN": 425,
    "fatigue_load_limit_kN": 18.2,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1800,
    "weight_g": 2720,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51316 belongs to the heavy-section 51300 thrust family of single-direction thrust ball bearings: 80 / 140 / 44 mm (shaft bore / OD / height). Reading the code: 513 is the dimension series (heavy-section 51300 thrust family), and 16 encodes the 80 mm bore (bore code x 5). At 44 mm of height the stack is compact for the 80 mm bore class, trading section height for the heavy-section load level. For a 80 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot. ",
    "applications": [
      "vertical water-pump and turbine thrust blocks",
      "large crane hook and swivel assemblies",
      "rolling-mill screwdown and adjustment screws",
      "heavy press and forging-machine thrust seats"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "At 80 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 513 heavy section buys capacity with a larger 140 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Swapping the shaft and housing washers is an easy assembly error on the 80 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51316 stack height of 44 mm and washer set differ from the double-direction execution.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 176 kN never saves a bearing that is running too lightly loaded at 1,200 r/min.",
      "The Ca 176/C0a 425 kN ratings and 18.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51316; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51316?",
        "a": "51316 is a single-direction thrust ball bearing to ISO 104: 80 mm shaft-washer bore, 140 mm outside diameter, 44 mm stack height (3.15 x 5.512 x 1.732 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 176 kN, C0a 425 kN and a 18.2 kN fatigue load limit Pu; the grease limiting speed is 1,200 r/min and the oil rating 1,800 r/min; mass about 2720 g."
      },
      {
        "q": "How is the 51316 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 16 encodes the 80 mm bore (bore code x 5). The 140 mm OD and 44 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51316 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51316?",
        "a": "At the 1,200 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51316?",
        "a": "The 80/140/44 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 176 kN / C0a 425 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51316-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×140×44 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51316"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51416",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51416",
    "series": "51400-series",
    "type": "thrust_ball",
    "d_mm": 80,
    "D_mm": 170,
    "B_mm": 68,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 270,
    "static_load_kN": 620,
    "fatigue_load_limit_kN": 25,
    "limiting_speed_rpm": 890,
    "max_rpm": 890,
    "speed_oil_rpm": 1300,
    "weight_g": 7770,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 80 x 170 x 68 mm, NTN 51416 sits in the extra-heavy 51400 thrust family of the single-direction thrust programme. Decoding 51416: 514 is the dimension series (extra-heavy 51400 thrust family), with 16 encodes the 80 mm bore (bore code x 5). On speed, the grease limiting speed is 890 r/min and the oil rating 1,300 r/min. Within the thrust-ball plan, 511 is the light section and 514 the heaviest for a given bore; moving up a series raises the C0a from 620 kN class figures at the cost of OD and height. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "At 80 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.",
      "The 890 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51416 has no radial capacity at all.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "The Ca 270/C0a 620 kN ratings and 25 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51416; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51416?",
        "a": "51416 is a single-direction thrust ball bearing to ISO 104: 80 mm shaft-washer bore, 170 mm outside diameter, 68 mm stack height (3.15 x 6.693 x 2.677 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 270 kN, C0a 620 kN and a 25 kN fatigue load limit Pu; the grease limiting speed is 890 r/min and the oil rating 1,300 r/min; mass about 7770 g."
      },
      {
        "q": "How is the 51416 designation structured?",
        "a": "514 is the dimension series (extra-heavy 51400 thrust family); 16 encodes the 80 mm bore (bore code x 5). The 170 mm OD and 68 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51416 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51416?",
        "a": "At the 890 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51416?",
        "a": "The 80/170/68 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 270 kN / C0a 620 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51416-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 80×170×68 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51416"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51117",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51117",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 85,
    "D_mm": 110,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 46,
    "static_load_kN": 150,
    "fatigue_load_limit_kN": 6.8,
    "limiting_speed_rpm": 2100,
    "max_rpm": 2100,
    "speed_oil_rpm": 3000,
    "weight_g": 444,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the light-section 51100 thrust family, 51117 measures 85 mm through the shaft washer, 110 mm over the outside and 19 mm in assembled height. NTN builds the number from 511 is the dimension series (light-section 51100 thrust family); 17 encodes the 85 mm bore (bore code x 5). The washer section here is 12.5 mm of radial height, and the catalogue couples it with Ca 46 kN / C0a 150 kN. For a 85 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks",
      "large crane hook and swivel assemblies"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "At 85 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 85 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "The 2,100 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "The C0a of 150 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "The Ca 46/C0a 150 kN ratings and 6.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51117; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51117?",
        "a": "51117 is a single-direction thrust ball bearing to ISO 104: 85 mm shaft-washer bore, 110 mm outside diameter, 19 mm stack height (3.346 x 4.331 x 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 46 kN, C0a 150 kN and a 6.8 kN fatigue load limit Pu; the grease limiting speed is 2,100 r/min and the oil rating 3,000 r/min; mass about 444 g."
      },
      {
        "q": "How is the 51117 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 17 encodes the 85 mm bore (bore code x 5). The 110 mm OD and 19 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51117 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51117?",
        "a": "At the 2,100 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51117?",
        "a": "The 85/110/19 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 46 kN / C0a 150 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51117-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51117"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51217",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51217",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 85,
    "D_mm": 125,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 95.5,
    "static_load_kN": 264,
    "fatigue_load_limit_kN": 11.6,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 2200,
    "weight_g": 1250,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51217 appears as a medium-section 51200 thrust family bearing with a 85 mm shaft washer, a 125 mm housing diameter and 31 mm of stack height. Decoding 51217: 512 is the dimension series (medium-section 51200 thrust family), with 17 encodes the 85 mm bore (bore code x 5). Flat-seat washers make the bearing tolerant of simple housings but demand square faces: the whole 95.5 kN rating assumes the load arrives truly axial. Size selection ends with the minimum-load check: at the 1,600 r/min class speed, the balls need a defined axial preload to keep rolling instead of skidding. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "heavy press and forging-machine thrust seats",
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "At 85 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 85 mm bore.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51217 stack height of 31 mm and washer set differ from the double-direction execution.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51217 stack height of 31 mm and washer set differ from the double-direction execution.",
      "The Ca 95.5/C0a 264 kN ratings and 11.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51217; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51217?",
        "a": "51217 is a single-direction thrust ball bearing to ISO 104: 85 mm shaft-washer bore, 125 mm outside diameter, 31 mm stack height (3.346 x 4.921 x 1.22 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 95.5 kN, C0a 264 kN and a 11.6 kN fatigue load limit Pu; the grease limiting speed is 1,600 r/min and the oil rating 2,200 r/min; mass about 1250 g."
      },
      {
        "q": "How is the 51217 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 17 encodes the 85 mm bore (bore code x 5). The 125 mm OD and 31 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51217 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51217?",
        "a": "At the 1,600 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51217?",
        "a": "The 85/125/31 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 95.5 kN / C0a 264 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51217-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51217"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51317",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51317",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 85,
    "D_mm": 150,
    "B_mm": 49,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 206,
    "static_load_kN": 490,
    "fatigue_load_limit_kN": 20.3,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1600,
    "weight_g": 3520,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The heavy-section 51300 thrust family entry 51317 stacks a shaft washer, ball-and-cage set and housing washer into 49 mm of height over a 85 mm bore. Two fields make up the code — 513 is the dimension series (heavy-section 51300 thrust family) and 17 encodes the 85 mm bore (bore code x 5). The static margin, C0a 490 kN against Ca 206 kN, is what carries slow oscillating or shock thrust without permanent raceway dents. Against a thrust roller bearing of the same 85 mm bore, this bearing is cheaper, quieter and happier at speed, but carries far less load per mm of section. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "rolling-mill screwdown and adjustment screws",
      "heavy press and forging-machine thrust seats",
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "At 85 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 513 heavy section buys capacity with a larger 150 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "The C0a of 490 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Single-direction means exactly that: thrust on 51317 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Shock thrust above C0a 490 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The Ca 206/C0a 490 kN ratings and 20.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51317; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51317?",
        "a": "51317 is a single-direction thrust ball bearing to ISO 104: 85 mm shaft-washer bore, 150 mm outside diameter, 49 mm stack height (3.346 x 5.906 x 1.929 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 206 kN, C0a 490 kN and a 20.3 kN fatigue load limit Pu; the grease limiting speed is 1,100 r/min and the oil rating 1,600 r/min; mass about 3520 g."
      },
      {
        "q": "How is the 51317 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 17 encodes the 85 mm bore (bore code x 5). The 150 mm OD and 49 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51317 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51317?",
        "a": "At the 1,100 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51317?",
        "a": "The 85/150/49 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 206 kN / C0a 490 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51317-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 85×150×49 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51317"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51417",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51417",
    "series": "51400-series",
    "type": "thrust_ball",
    "d_mm": 85,
    "D_mm": 180,
    "B_mm": 72,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 288,
    "static_load_kN": 685,
    "fatigue_load_limit_kN": 26.8,
    "limiting_speed_rpm": 840,
    "max_rpm": 840,
    "speed_oil_rpm": 1200,
    "weight_g": 9170,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51417 is the 85 mm member of NTN's extra-heavy 51400 thrust family: 180 mm across the washers, 72 mm tall. NTN builds the number from 514 is the dimension series (extra-heavy 51400 thrust family); 17 encodes the 85 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 288 kN against C0a 685 kN — a static/dynamic ratio of 2.38 that is the signature of a thrust raceway. Selection starts from the load direction: if thrust ever reverses, plan a second thrust bearing (or a double-direction execution) rather than relying on the unloaded raceway. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 180 mm OD already tilts the raceway and concentrates the 685 kN static capacity on a few balls. ",
    "applications": [
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks",
      "large crane hook and swivel assemblies",
      "rolling-mill screwdown and adjustment screws"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "At 85 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51417 stack height of 72 mm and washer set differ from the double-direction execution.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 288 kN never saves a bearing that is running too lightly loaded at 840 r/min.",
      "Swapping the shaft and housing washers is an easy assembly error on the 85 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "The Ca 288/C0a 685 kN ratings and 26.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51417; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51417?",
        "a": "51417 is a single-direction thrust ball bearing to ISO 104: 85 mm shaft-washer bore, 180 mm outside diameter, 72 mm stack height (3.346 x 7.087 x 2.835 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 288 kN, C0a 685 kN and a 26.8 kN fatigue load limit Pu; the grease limiting speed is 840 r/min and the oil rating 1,200 r/min; mass about 9170 g."
      },
      {
        "q": "How is the 51417 designation structured?",
        "a": "514 is the dimension series (extra-heavy 51400 thrust family); 17 encodes the 85 mm bore (bore code x 5). The 180 mm OD and 72 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51417 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51417?",
        "a": "At the 840 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51417?",
        "a": "The 85/180/72 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 288 kN / C0a 685 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51417-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51417",
      "51417"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51118",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51118",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 90,
    "D_mm": 120,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 59.5,
    "static_load_kN": 190,
    "fatigue_load_limit_kN": 8.35,
    "limiting_speed_rpm": 1900,
    "max_rpm": 1900,
    "speed_oil_rpm": 2700,
    "weight_g": 687,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51118 is an NTN single-direction thrust ball bearing of the light-section 51100 thrust family: 90 mm bore, 120 mm outside diameter, 22 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. The designation is 511 is the dimension series (light-section 51100 thrust family) plus 18 encodes the 90 mm bore (bore code x 5). The ball-and-cage set is separable from both washers, which is why the mounting order (shaft washer first, then cage, then housing washer) matters. Against a thrust roller bearing of the same 90 mm bore, this bearing is cheaper, quieter and happier at speed, but carries far less load per mm of section. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 120 mm OD already tilts the raceway and concentrates the 190 kN static capacity on a few balls. ",
    "applications": [
      "vertical water-pump and turbine thrust blocks",
      "large crane hook and swivel assemblies",
      "rolling-mill screwdown and adjustment screws",
      "heavy press and forging-machine thrust seats"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "At 90 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 90 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Shock thrust above C0a 190 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Shock thrust above C0a 190 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51118 has no radial capacity at all.",
      "The Ca 59.5/C0a 190 kN ratings and 8.35 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51118; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51118?",
        "a": "51118 is a single-direction thrust ball bearing to ISO 104: 90 mm shaft-washer bore, 120 mm outside diameter, 22 mm stack height (3.543 x 4.724 x 0.866 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 59.5 kN, C0a 190 kN and a 8.35 kN fatigue load limit Pu; the grease limiting speed is 1,900 r/min and the oil rating 2,700 r/min; mass about 687 g."
      },
      {
        "q": "How is the 51118 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 18 encodes the 90 mm bore (bore code x 5). The 120 mm OD and 22 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51118 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51118?",
        "a": "At the 1,900 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51118?",
        "a": "The 90/120/22 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 59.5 kN / C0a 190 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51118-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51118"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51218",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51218",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 90,
    "D_mm": 135,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 117,
    "static_load_kN": 325,
    "fatigue_load_limit_kN": 13.9,
    "limiting_speed_rpm": 1400,
    "max_rpm": 1400,
    "speed_oil_rpm": 2000,
    "weight_g": 1700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51218 belongs to the medium-section 51200 thrust family of single-direction thrust ball bearings: 90 / 135 / 35 mm (shaft bore / OD / height). NTN builds the number from 512 is the dimension series (medium-section 51200 thrust family); 18 encodes the 90 mm bore (bore code x 5). NTN prints 117 kN axial dynamic and 325 kN axial static for this size and a 13.9 kN fatigue load limit Pu. Within the thrust-ball plan, 511 is the light section and 514 the heaviest for a given bore; moving up a series raises the C0a from 325 kN class figures at the cost of OD and height. The shaft washer (bore 90 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks",
      "large crane hook and swivel assemblies"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "At 90 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 90 mm bore.",
      "The 1,400 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "Single-direction means exactly that: thrust on 51218 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "The Ca 117/C0a 325 kN ratings and 13.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51218; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51218?",
        "a": "51218 is a single-direction thrust ball bearing to ISO 104: 90 mm shaft-washer bore, 135 mm outside diameter, 35 mm stack height (3.543 x 5.315 x 1.378 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 117 kN, C0a 325 kN and a 13.9 kN fatigue load limit Pu; the grease limiting speed is 1,400 r/min and the oil rating 2,000 r/min; mass about 1700 g."
      },
      {
        "q": "How is the 51218 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 18 encodes the 90 mm bore (bore code x 5). The 135 mm OD and 35 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51218 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51218?",
        "a": "At the 1,400 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51218?",
        "a": "The 90/135/35 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 117 kN / C0a 325 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51218-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×135×35 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51218"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51318",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51318",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 90,
    "D_mm": 155,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 213,
    "static_load_kN": 525,
    "fatigue_load_limit_kN": 21.3,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1600,
    "weight_g": 3740,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 90 x 155 x 50 mm, NTN 51318 sits in the heavy-section 51300 thrust family of the single-direction thrust programme. Decoding 51318: 513 is the dimension series (heavy-section 51300 thrust family), with 18 encodes the 90 mm bore (bore code x 5). The washer section here is 32.5 mm of radial height, and the catalogue couples it with Ca 213 kN / C0a 525 kN. If the duty is high speed with light thrust, check the minimum axial load formula first; a too-large thrust ball bearing fails by skid long before its Ca of 213 kN is ever approached. The shaft washer (bore 90 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "At 90 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 513 heavy section buys capacity with a larger 155 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51318 has no radial capacity at all.",
      "The C0a of 525 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "The Ca 213/C0a 525 kN ratings and 21.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51318; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51318?",
        "a": "51318 is a single-direction thrust ball bearing to ISO 104: 90 mm shaft-washer bore, 155 mm outside diameter, 50 mm stack height (3.543 x 6.102 x 1.969 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 213 kN, C0a 525 kN and a 21.3 kN fatigue load limit Pu; the grease limiting speed is 1,100 r/min and the oil rating 1,600 r/min; mass about 3740 g."
      },
      {
        "q": "How is the 51318 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 18 encodes the 90 mm bore (bore code x 5). The 155 mm OD and 50 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51318 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51318?",
        "a": "At the 1,100 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51318?",
        "a": "The 90/155/50 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 213 kN / C0a 525 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51318-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 90×155×50 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51318"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51418",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51418",
    "series": "51400-series",
    "type": "thrust_ball",
    "d_mm": 90,
    "D_mm": 190,
    "B_mm": 77,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 305,
    "static_load_kN": 750,
    "fatigue_load_limit_kN": 28.6,
    "limiting_speed_rpm": 790,
    "max_rpm": 790,
    "speed_oil_rpm": 1100,
    "weight_g": 11000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the extra-heavy 51400 thrust family, 51418 measures 90 mm through the shaft washer, 190 mm over the outside and 77 mm in assembled height. The designation is 514 is the dimension series (extra-heavy 51400 thrust family) plus 18 encodes the 90 mm bore (bore code x 5). Flat-seat washers make the bearing tolerant of simple housings but demand square faces: the whole 305 kN rating assumes the load arrives truly axial. Choose the extra-heavy 51400 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "large crane hook and swivel assemblies",
      "rolling-mill screwdown and adjustment screws",
      "heavy press and forging-machine thrust seats",
      "ship winch and capstan thrust shafts"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "At 90 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51418 has no radial capacity at all.",
      "Swapping the shaft and housing washers is an easy assembly error on the 90 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51418 stack height of 77 mm and washer set differ from the double-direction execution.",
      "The Ca 305/C0a 750 kN ratings and 28.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51418; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51418?",
        "a": "51418 is a single-direction thrust ball bearing to ISO 104: 90 mm shaft-washer bore, 190 mm outside diameter, 77 mm stack height (3.543 x 7.48 x 3.031 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 305 kN, C0a 750 kN and a 28.6 kN fatigue load limit Pu; the grease limiting speed is 790 r/min and the oil rating 1,100 r/min; mass about 11000 g."
      },
      {
        "q": "How is the 51418 designation structured?",
        "a": "514 is the dimension series (extra-heavy 51400 thrust family); 18 encodes the 90 mm bore (bore code x 5). The 190 mm OD and 77 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51418 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51418?",
        "a": "At the 790 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51418?",
        "a": "The 90/190/77 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 305 kN / C0a 750 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51418-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=226",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51418",
      "51418"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51120",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51120",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 100,
    "D_mm": 135,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 85,
    "static_load_kN": 268,
    "fatigue_load_limit_kN": 11.2,
    "limiting_speed_rpm": 1700,
    "max_rpm": 1700,
    "speed_oil_rpm": 2400,
    "weight_g": 987,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51120 belongs to the light-section 51100 thrust family of single-direction thrust ball bearings: 100 / 135 / 25 mm (shaft bore / OD / height). NTN builds the number from 511 is the dimension series (light-section 51100 thrust family); 20 encodes the 100 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 85 kN against C0a 268 kN — a static/dynamic ratio of 3.15 that is the signature of a thrust raceway. Choose the light-section 51100 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks",
      "large crane hook and swivel assemblies",
      "rolling-mill screwdown and adjustment screws"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "At 100 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 100 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51120 has no radial capacity at all.",
      "Single-direction means exactly that: thrust on 51120 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Swapping the shaft and housing washers is an easy assembly error on the 100 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "The Ca 85/C0a 268 kN ratings and 11.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51120; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51120?",
        "a": "51120 is a single-direction thrust ball bearing to ISO 104: 100 mm shaft-washer bore, 135 mm outside diameter, 25 mm stack height (3.937 x 5.315 x 0.984 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 85 kN, C0a 268 kN and a 11.2 kN fatigue load limit Pu; the grease limiting speed is 1,700 r/min and the oil rating 2,400 r/min; mass about 987 g."
      },
      {
        "q": "How is the 51120 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 20 encodes the 100 mm bore (bore code x 5). The 135 mm OD and 25 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51120 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51120?",
        "a": "At the 1,700 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51120?",
        "a": "The 100/135/25 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 85 kN / C0a 268 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51120-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51120"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51220",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51220",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 100,
    "D_mm": 150,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 147,
    "static_load_kN": 410,
    "fatigue_load_limit_kN": 16.6,
    "limiting_speed_rpm": 1300,
    "max_rpm": 1300,
    "speed_oil_rpm": 1800,
    "weight_g": 2290,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 100 x 150 x 38 mm, NTN 51220 sits in the medium-section 51200 thrust family of the single-direction thrust programme. Decoding 51220: 512 is the dimension series (medium-section 51200 thrust family), with 20 encodes the 100 mm bore (bore code x 5). Catalogue mass is about 2290 g for the full washer-and-cage stack. For a 100 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot. ",
    "applications": [
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "At 100 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 100 mm bore.",
      "Single-direction means exactly that: thrust on 51220 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 147 kN never saves a bearing that is running too lightly loaded at 1,300 r/min.",
      "The 1,300 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "The Ca 147/C0a 410 kN ratings and 16.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51220; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51220?",
        "a": "51220 is a single-direction thrust ball bearing to ISO 104: 100 mm shaft-washer bore, 150 mm outside diameter, 38 mm stack height (3.937 x 5.906 x 1.496 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 147 kN, C0a 410 kN and a 16.6 kN fatigue load limit Pu; the grease limiting speed is 1,300 r/min and the oil rating 1,800 r/min; mass about 2290 g."
      },
      {
        "q": "How is the 51220 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 20 encodes the 100 mm bore (bore code x 5). The 150 mm OD and 38 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51220 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51220?",
        "a": "At the 1,300 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51220?",
        "a": "The 100/150/38 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 147 kN / C0a 410 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51220-SKF",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 100×150×38 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51220"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51320",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51320",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 100,
    "D_mm": 170,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 237,
    "static_load_kN": 595,
    "fatigue_load_limit_kN": 23.1,
    "limiting_speed_rpm": 990,
    "max_rpm": 990,
    "speed_oil_rpm": 1400,
    "weight_g": 4880,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the heavy-section 51300 thrust family, 51320 measures 100 mm through the shaft washer, 170 mm over the outside and 55 mm in assembled height. Two fields make up the code — 513 is the dimension series (heavy-section 51300 thrust family) and 20 encodes the 100 mm bore (bore code x 5). On speed, the grease limiting speed is 990 r/min and the oil rating 1,400 r/min. The 100/170/55 envelope follows ISO 104, so dimensional interchange holds between makers — raceway osculation and ratings do not automatically follow. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot. ",
    "applications": [
      "heavy press and forging-machine thrust seats",
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "At 100 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 513 heavy section buys capacity with a larger 170 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51320 stack height of 55 mm and washer set differ from the double-direction execution.",
      "Swapping the shaft and housing washers is an easy assembly error on the 100 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "The Ca 237/C0a 595 kN ratings and 23.1 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51320; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51320?",
        "a": "51320 is a single-direction thrust ball bearing to ISO 104: 100 mm shaft-washer bore, 170 mm outside diameter, 55 mm stack height (3.937 x 6.693 x 2.165 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 237 kN, C0a 595 kN and a 23.1 kN fatigue load limit Pu; the grease limiting speed is 990 r/min and the oil rating 1,400 r/min; mass about 4880 g."
      },
      {
        "q": "How is the 51320 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 20 encodes the 100 mm bore (bore code x 5). The 170 mm OD and 55 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51320 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51320?",
        "a": "At the 990 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51320?",
        "a": "The 100/170/55 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 237 kN / C0a 595 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51320-SKF",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51320"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51420",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51420",
    "series": "51400-series",
    "type": "thrust_ball",
    "d_mm": 100,
    "D_mm": 210,
    "B_mm": 85,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 370,
    "static_load_kN": 970,
    "fatigue_load_limit_kN": 35,
    "limiting_speed_rpm": 710,
    "max_rpm": 710,
    "speed_oil_rpm": 1000,
    "weight_g": 14700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51420 appears as a extra-heavy 51400 thrust family bearing with a 100 mm shaft washer, a 210 mm housing diameter and 85 mm of stack height. NTN builds the number from 514 is the dimension series (extra-heavy 51400 thrust family); 20 encodes the 100 mm bore (bore code x 5). The ball-and-cage set is separable from both washers, which is why the mounting order (shaft washer first, then cage, then housing washer) matters. If the duty is high speed with light thrust, check the minimum axial load formula first; a too-large thrust ball bearing fails by skid long before its Ca of 370 kN is ever approached. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "vertical water-pump and turbine thrust blocks",
      "large crane hook and swivel assemblies",
      "rolling-mill screwdown and adjustment screws",
      "heavy press and forging-machine thrust seats"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "At 100 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "The C0a of 970 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51420 has no radial capacity at all.",
      "The Ca 370/C0a 970 kN ratings and 35 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51420; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51420?",
        "a": "51420 is a single-direction thrust ball bearing to ISO 104: 100 mm shaft-washer bore, 210 mm outside diameter, 85 mm stack height (3.937 x 8.268 x 3.346 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 370 kN, C0a 970 kN and a 35 kN fatigue load limit Pu; the grease limiting speed is 710 r/min and the oil rating 1,000 r/min; mass about 14700 g."
      },
      {
        "q": "How is the 51420 designation structured?",
        "a": "514 is the dimension series (extra-heavy 51400 thrust family); 20 encodes the 100 mm bore (bore code x 5). The 210 mm OD and 85 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51420 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51420?",
        "a": "At the 710 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51420?",
        "a": "The 100/210/85 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 370 kN / C0a 970 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51420-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51420",
      "51420"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51122-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51122",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 110,
    "D_mm": 145,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 87,
    "static_load_kN": 288,
    "fatigue_load_limit_kN": 11.5,
    "limiting_speed_rpm": 1600,
    "max_rpm": 1600,
    "speed_oil_rpm": 2300,
    "weight_g": 1070,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51122 is an NTN single-direction thrust ball bearing of the light-section 51100 thrust family: 110 mm bore, 145 mm outside diameter, 25 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. The designation is 511 is the dimension series (light-section 51100 thrust family) plus 22 encodes the 110 mm bore (bore code x 5). The static margin, C0a 288 kN against Ca 87 kN, is what carries slow oscillating or shock thrust without permanent raceway dents. Selection starts from the load direction: if thrust ever reverses, plan a second thrust bearing (or a double-direction execution) rather than relying on the unloaded raceway. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "At 110 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 110 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 87 kN never saves a bearing that is running too lightly loaded at 1,600 r/min.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "Shock thrust above C0a 288 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The Ca 87/C0a 288 kN ratings and 11.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51122; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51122?",
        "a": "51122 is a single-direction thrust ball bearing to ISO 104: 110 mm shaft-washer bore, 145 mm outside diameter, 25 mm stack height (4.331 x 5.709 x 0.984 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 87 kN, C0a 288 kN and a 11.5 kN fatigue load limit Pu; the grease limiting speed is 1,600 r/min and the oil rating 2,300 r/min; mass about 1070 g."
      },
      {
        "q": "How is the 51122 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 22 encodes the 110 mm bore (bore code x 5). The 145 mm OD and 25 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51122 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51122?",
        "a": "At the 1,600 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51122?",
        "a": "The 110/145/25 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 87 kN / C0a 288 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51122",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51122",
      "51122-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51222-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51222",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 110,
    "D_mm": 160,
    "B_mm": 38,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 153,
    "static_load_kN": 450,
    "fatigue_load_limit_kN": 17.5,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1800,
    "weight_g": 2460,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the medium-section 51200 thrust family, 51222 measures 110 mm through the shaft washer, 160 mm over the outside and 38 mm in assembled height. NTN builds the number from 512 is the dimension series (medium-section 51200 thrust family); 22 encodes the 110 mm bore (bore code x 5). At 38 mm of height the stack is compact for the 110 mm bore class, trading section height for the medium-section load level. Within the thrust-ball plan, 511 is the light section and 514 the heaviest for a given bore; moving up a series raises the C0a from 450 kN class figures at the cost of OD and height. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "ship winch and capstan thrust shafts",
      "crusher main-shaft thrust supports",
      "large rotary-table and index-table thrust rings",
      "vertical water-pump and turbine thrust blocks"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "At 110 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 110 mm bore.",
      "The 1,200 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 153 kN never saves a bearing that is running too lightly loaded at 1,200 r/min.",
      "The Ca 153/C0a 450 kN ratings and 17.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51222; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51222?",
        "a": "51222 is a single-direction thrust ball bearing to ISO 104: 110 mm shaft-washer bore, 160 mm outside diameter, 38 mm stack height (4.331 x 6.299 x 1.496 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 153 kN, C0a 450 kN and a 17.5 kN fatigue load limit Pu; the grease limiting speed is 1,200 r/min and the oil rating 1,800 r/min; mass about 2460 g."
      },
      {
        "q": "How is the 51222 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 22 encodes the 110 mm bore (bore code x 5). The 160 mm OD and 38 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51222 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51222?",
        "a": "At the 1,200 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51222?",
        "a": "The 110/160/38 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 153 kN / C0a 450 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51222",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×160×38 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51222",
      "51222-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51322",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51322",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 110,
    "D_mm": 190,
    "B_mm": 63,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 267,
    "static_load_kN": 705,
    "fatigue_load_limit_kN": 25.9,
    "limiting_speed_rpm": 870,
    "max_rpm": 870,
    "speed_oil_rpm": 1200,
    "weight_g": 7670,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51322 appears as a heavy-section 51300 thrust family bearing with a 110 mm shaft washer, a 190 mm housing diameter and 63 mm of stack height. NTN builds the number from 513 is the dimension series (heavy-section 51300 thrust family); 22 encodes the 110 mm bore (bore code x 5). Flat-seat washers make the bearing tolerant of simple housings but demand square faces: the whole 267 kN rating assumes the load arrives truly axial. For a 110 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. The shaft washer (bore 110 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "vertical water-pump and turbine thrust blocks",
      "large crane hook and swivel assemblies",
      "rolling-mill screwdown and adjustment screws",
      "heavy press and forging-machine thrust seats"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "At 110 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.",
      "The 513 heavy section buys capacity with a larger 190 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Swapping the shaft and housing washers is an easy assembly error on the 110 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "The C0a of 705 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51322 stack height of 63 mm and washer set differ from the double-direction execution.",
      "The Ca 267/C0a 705 kN ratings and 25.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51322; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51322?",
        "a": "51322 is a single-direction thrust ball bearing to ISO 104: 110 mm shaft-washer bore, 190 mm outside diameter, 63 mm stack height (4.331 x 7.48 x 2.48 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 267 kN, C0a 705 kN and a 25.9 kN fatigue load limit Pu; the grease limiting speed is 870 r/min and the oil rating 1,200 r/min; mass about 7670 g."
      },
      {
        "q": "How is the 51322 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 22 encodes the 110 mm bore (bore code x 5). The 190 mm OD and 63 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51322 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51322?",
        "a": "At the 870 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51322?",
        "a": "The 110/190/63 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 267 kN / C0a 705 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51322-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 110×190×63 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51322",
      "51322"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51124-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51124",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 120,
    "D_mm": 155,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 89,
    "static_load_kN": 310,
    "fatigue_load_limit_kN": 11.8,
    "limiting_speed_rpm": 1500,
    "max_rpm": 1500,
    "speed_oil_rpm": 2200,
    "weight_g": 1110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51124 is an NTN single-direction thrust ball bearing of the light-section 51100 thrust family: 120 mm bore, 155 mm outside diameter, 25 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. NTN builds the number from 511 is the dimension series (light-section 51100 thrust family); 24 encodes the 120 mm bore (bore code x 5). Catalogue mass is about 1110 g for the full washer-and-cage stack. Choose the light-section 51100 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "For a 120 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 120 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51124 has no radial capacity at all.",
      "Single-direction means exactly that: thrust on 51124 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The 1,500 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "The Ca 89/C0a 310 kN ratings and 11.8 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51124; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51124?",
        "a": "51124 is a single-direction thrust ball bearing to ISO 104: 120 mm shaft-washer bore, 155 mm outside diameter, 25 mm stack height (4.724 x 6.102 x 0.984 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 89 kN, C0a 310 kN and a 11.8 kN fatigue load limit Pu; the grease limiting speed is 1,500 r/min and the oil rating 2,200 r/min; mass about 1110 g."
      },
      {
        "q": "How is the 51124 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 24 encodes the 120 mm bore (bore code x 5). The 155 mm OD and 25 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51124 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51124?",
        "a": "At the 1,500 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51124?",
        "a": "The 120/155/25 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 89 kN / C0a 310 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51124",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51124",
      "51124-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51224-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51224",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 120,
    "D_mm": 170,
    "B_mm": 39,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 154,
    "static_load_kN": 470,
    "fatigue_load_limit_kN": 17.7,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1700,
    "weight_g": 2710,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51224 appears as a medium-section 51200 thrust family bearing with a 120 mm shaft washer, a 170 mm housing diameter and 39 mm of stack height. The designation is 512 is the dimension series (medium-section 51200 thrust family) plus 24 encodes the 120 mm bore (bore code x 5). Because the contact points run at 90 deg to the shaft, none of the rating is available for radial load — not even incidentally. For a 120 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "For a 120 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 120 mm bore.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51224 has no radial capacity at all.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 154 kN never saves a bearing that is running too lightly loaded at 1,200 r/min.",
      "Single-direction means exactly that: thrust on 51224 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The Ca 154/C0a 470 kN ratings and 17.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51224; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51224?",
        "a": "51224 is a single-direction thrust ball bearing to ISO 104: 120 mm shaft-washer bore, 170 mm outside diameter, 39 mm stack height (4.724 x 6.693 x 1.535 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 154 kN, C0a 470 kN and a 17.7 kN fatigue load limit Pu; the grease limiting speed is 1,200 r/min and the oil rating 1,700 r/min; mass about 2710 g."
      },
      {
        "q": "How is the 51224 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 24 encodes the 120 mm bore (bore code x 5). The 170 mm OD and 39 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51224 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51224?",
        "a": "At the 1,200 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51224?",
        "a": "The 120/170/39 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 154 kN / C0a 470 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51224",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×170×39 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51224",
      "51224-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51324",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51324",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 120,
    "D_mm": 210,
    "B_mm": 70,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 296,
    "static_load_kN": 805,
    "fatigue_load_limit_kN": 28.3,
    "limiting_speed_rpm": 780,
    "max_rpm": 780,
    "speed_oil_rpm": 1100,
    "weight_g": 10800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The heavy-section 51300 thrust family entry 51324 stacks a shaft washer, ball-and-cage set and housing washer into 70 mm of height over a 120 mm bore. Reading the code: 513 is the dimension series (heavy-section 51300 thrust family), and 24 encodes the 120 mm bore (bore code x 5). At 70 mm of height the stack is compact for the 120 mm bore class, trading section height for the heavy-section load level. If the duty is high speed with light thrust, check the minimum axial load formula first; a too-large thrust ball bearing fails by skid long before its Ca of 296 kN is ever approached. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "For a 120 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 513 heavy section buys capacity with a larger 210 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 296 kN never saves a bearing that is running too lightly loaded at 780 r/min.",
      "The Ca 296/C0a 805 kN ratings and 28.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51324; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51324?",
        "a": "51324 is a single-direction thrust ball bearing to ISO 104: 120 mm shaft-washer bore, 210 mm outside diameter, 70 mm stack height (4.724 x 8.268 x 2.756 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 296 kN, C0a 805 kN and a 28.3 kN fatigue load limit Pu; the grease limiting speed is 780 r/min and the oil rating 1,100 r/min; mass about 10800 g."
      },
      {
        "q": "How is the 51324 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 24 encodes the 120 mm bore (bore code x 5). The 210 mm OD and 70 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51324 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51324?",
        "a": "At the 780 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51324?",
        "a": "The 120/210/70 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 296 kN / C0a 805 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51324-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 120×210×70 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51324",
      "51324"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51126-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51126",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 130,
    "D_mm": 170,
    "B_mm": 30,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 104,
    "static_load_kN": 350,
    "fatigue_load_limit_kN": 13,
    "limiting_speed_rpm": 1300,
    "max_rpm": 1300,
    "speed_oil_rpm": 1900,
    "weight_g": 1730,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51126 is an NTN single-direction thrust ball bearing of the light-section 51100 thrust family: 130 mm bore, 170 mm outside diameter, 30 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. The designation is 511 is the dimension series (light-section 51100 thrust family) plus 26 encodes the 130 mm bore (bore code x 5). On speed, the grease limiting speed is 1,300 r/min and the oil rating 1,900 r/min. Choose the light-section 51100 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "For a 130 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 130 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "The C0a of 350 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "The C0a of 350 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "The Ca 104/C0a 350 kN ratings and 13 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51126; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51126?",
        "a": "51126 is a single-direction thrust ball bearing to ISO 104: 130 mm shaft-washer bore, 170 mm outside diameter, 30 mm stack height (5.118 x 6.693 x 1.181 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 104 kN, C0a 350 kN and a 13 kN fatigue load limit Pu; the grease limiting speed is 1,300 r/min and the oil rating 1,900 r/min; mass about 1730 g."
      },
      {
        "q": "How is the 51126 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 26 encodes the 130 mm bore (bore code x 5). The 170 mm OD and 30 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51126 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51126?",
        "a": "At the 1,300 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51126?",
        "a": "The 130/170/30 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 104 kN / C0a 350 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51126",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×170×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "51126",
      "51126-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51226-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51226",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 130,
    "D_mm": 190,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 191,
    "static_load_kN": 565,
    "fatigue_load_limit_kN": 20.2,
    "limiting_speed_rpm": 1000,
    "max_rpm": 1000,
    "speed_oil_rpm": 1500,
    "weight_g": 4220,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51226 appears as a medium-section 51200 thrust family bearing with a 130 mm shaft washer, a 190 mm housing diameter and 45 mm of stack height. NTN builds the number from 512 is the dimension series (medium-section 51200 thrust family); 26 encodes the 130 mm bore (bore code x 5). Flat-seat washers make the bearing tolerant of simple housings but demand square faces: the whole 191 kN rating assumes the load arrives truly axial. Against a thrust roller bearing of the same 130 mm bore, this bearing is cheaper, quieter and happier at speed, but carries far less load per mm of section. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 190 mm OD already tilts the raceway and concentrates the 565 kN static capacity on a few balls. ",
    "applications": [
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "For a 130 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 130 mm bore.",
      "Single-direction means exactly that: thrust on 51226 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51226 stack height of 45 mm and washer set differ from the double-direction execution.",
      "The Ca 191/C0a 565 kN ratings and 20.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51226; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51226?",
        "a": "51226 is a single-direction thrust ball bearing to ISO 104: 130 mm shaft-washer bore, 190 mm outside diameter, 45 mm stack height (5.118 x 7.48 x 1.772 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 191 kN, C0a 565 kN and a 20.2 kN fatigue load limit Pu; the grease limiting speed is 1,000 r/min and the oil rating 1,500 r/min; mass about 4220 g."
      },
      {
        "q": "How is the 51226 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 26 encodes the 130 mm bore (bore code x 5). The 190 mm OD and 45 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51226 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51226?",
        "a": "At the 1,000 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51226?",
        "a": "The 130/190/45 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 191 kN / C0a 565 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51226",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51226",
      "51226",
      "51226-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51326",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51326",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 130,
    "D_mm": 225,
    "B_mm": 75,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 330,
    "static_load_kN": 960,
    "fatigue_load_limit_kN": 32.5,
    "limiting_speed_rpm": 720,
    "max_rpm": 720,
    "speed_oil_rpm": 1000,
    "weight_g": 12700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51326 is the 130 mm member of NTN's heavy-section 51300 thrust family: 225 mm across the washers, 75 mm tall. Decoding 51326: 513 is the dimension series (heavy-section 51300 thrust family), with 26 encodes the 130 mm bore (bore code x 5). The washer section here is 47.5 mm of radial height, and the catalogue couples it with Ca 330 kN / C0a 960 kN. Within the thrust-ball plan, 511 is the light section and 514 the heaviest for a given bore; moving up a series raises the C0a from 960 kN class figures at the cost of OD and height. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "For a 130 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 513 heavy section buys capacity with a larger 225 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Single-direction means exactly that: thrust on 51326 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Shock thrust above C0a 960 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The C0a of 960 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "The Ca 330/C0a 960 kN ratings and 32.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51326; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51326?",
        "a": "51326 is a single-direction thrust ball bearing to ISO 104: 130 mm shaft-washer bore, 225 mm outside diameter, 75 mm stack height (5.118 x 8.858 x 2.953 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 330 kN, C0a 960 kN and a 32.5 kN fatigue load limit Pu; the grease limiting speed is 720 r/min and the oil rating 1,000 r/min; mass about 12700 g."
      },
      {
        "q": "How is the 51326 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 26 encodes the 130 mm bore (bore code x 5). The 225 mm OD and 75 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51326 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51326?",
        "a": "At the 720 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51326?",
        "a": "The 130/225/75 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 330 kN / C0a 960 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51326-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 130×225×75 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51326",
      "51326"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51128-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51128",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 140,
    "D_mm": 180,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 107,
    "static_load_kN": 375,
    "fatigue_load_limit_kN": 13.4,
    "limiting_speed_rpm": 1300,
    "max_rpm": 1300,
    "speed_oil_rpm": 1800,
    "weight_g": 1900,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51128 is an NTN single-direction thrust ball bearing of the light-section 51100 thrust family: 140 mm bore, 180 mm outside diameter, 31 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. NTN builds the number from 511 is the dimension series (light-section 51100 thrust family); 28 encodes the 140 mm bore (bore code x 5). NTN prints 107 kN axial dynamic and 375 kN axial static for this size and a 13.4 kN fatigue load limit Pu. The 140/180/31 envelope follows ISO 104, so dimensional interchange holds between makers — raceway osculation and ratings do not automatically follow. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "For a 140 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 140 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51128 stack height of 31 mm and washer set differ from the double-direction execution.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "The Ca 107/C0a 375 kN ratings and 13.4 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51128; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51128?",
        "a": "51128 is a single-direction thrust ball bearing to ISO 104: 140 mm shaft-washer bore, 180 mm outside diameter, 31 mm stack height (5.512 x 7.087 x 1.22 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 107 kN, C0a 375 kN and a 13.4 kN fatigue load limit Pu; the grease limiting speed is 1,300 r/min and the oil rating 1,800 r/min; mass about 1900 g."
      },
      {
        "q": "How is the 51128 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 28 encodes the 140 mm bore (bore code x 5). The 180 mm OD and 31 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51128 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51128?",
        "a": "At the 1,300 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51128?",
        "a": "The 140/180/31 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 107 kN / C0a 375 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51128",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×180×31 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51128",
      "51128",
      "51128-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51228-NTN",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51228",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 140,
    "D_mm": 200,
    "B_mm": 46,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 193,
    "static_load_kN": 595,
    "fatigue_load_limit_kN": 20.6,
    "limiting_speed_rpm": 980,
    "max_rpm": 980,
    "speed_oil_rpm": 1400,
    "weight_g": 4770,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51228 appears as a medium-section 51200 thrust family bearing with a 140 mm shaft washer, a 200 mm housing diameter and 46 mm of stack height. Decoding 51228: 512 is the dimension series (medium-section 51200 thrust family), with 28 encodes the 140 mm bore (bore code x 5). The static margin, C0a 595 kN against Ca 193 kN, is what carries slow oscillating or shock thrust without permanent raceway dents. If the duty is high speed with light thrust, check the minimum axial load formula first; a too-large thrust ball bearing fails by skid long before its Ca of 193 kN is ever approached. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot. ",
    "applications": [
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "For a 140 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 140 mm bore.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51228 stack height of 46 mm and washer set differ from the double-direction execution.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51228 has no radial capacity at all.",
      "Shock thrust above C0a 595 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The Ca 193/C0a 595 kN ratings and 20.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51228; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51228?",
        "a": "51228 is a single-direction thrust ball bearing to ISO 104: 140 mm shaft-washer bore, 200 mm outside diameter, 46 mm stack height (5.512 x 7.874 x 1.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 193 kN, C0a 595 kN and a 20.6 kN fatigue load limit Pu; the grease limiting speed is 980 r/min and the oil rating 1,400 r/min; mass about 4770 g."
      },
      {
        "q": "How is the 51228 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 28 encodes the 140 mm bore (bore code x 5). The 200 mm OD and 46 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51228 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51228?",
        "a": "At the 980 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51228?",
        "a": "The 140/200/46 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 193 kN / C0a 595 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51228",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51228",
      "51228",
      "51228-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51328",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51328",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 140,
    "D_mm": 240,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 350,
    "static_load_kN": 1050,
    "fatigue_load_limit_kN": 34.5,
    "limiting_speed_rpm": 670,
    "max_rpm": 670,
    "speed_oil_rpm": 960,
    "weight_g": 15300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51328 is an NTN single-direction thrust ball bearing of the heavy-section 51300 thrust family: 140 mm bore, 240 mm outside diameter, 80 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. The designation is 513 is the dimension series (heavy-section 51300 thrust family) plus 28 encodes the 140 mm bore (bore code x 5). Catalogue mass is about 15300 g for the full washer-and-cage stack. Choose the heavy-section 51300 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "For a 140 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 513 heavy section buys capacity with a larger 240 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Single-direction means exactly that: thrust on 51328 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The 670 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "The Ca 350/C0a 1050 kN ratings and 34.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51328; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51328?",
        "a": "51328 is a single-direction thrust ball bearing to ISO 104: 140 mm shaft-washer bore, 240 mm outside diameter, 80 mm stack height (5.512 x 9.449 x 3.15 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 350 kN, C0a 1050 kN and a 34.5 kN fatigue load limit Pu; the grease limiting speed is 670 r/min and the oil rating 960 r/min; mass about 15300 g."
      },
      {
        "q": "How is the 51328 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 28 encodes the 140 mm bore (bore code x 5). The 240 mm OD and 80 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51328 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51328?",
        "a": "At the 670 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51328?",
        "a": "The 140/240/80 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 350 kN / C0a 1050 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51328-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 140×240×80 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51328",
      "51328"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51130",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51130",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 150,
    "D_mm": 190,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 109,
    "static_load_kN": 400,
    "fatigue_load_limit_kN": 13.9,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1800,
    "weight_g": 2000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51130 is the 150 mm member of NTN's light-section 51100 thrust family: 190 mm across the washers, 31 mm tall. Reading the code: 511 is the dimension series (light-section 51100 thrust family), and 30 encodes the 150 mm bore (bore code x 5). NTN prints 109 kN axial dynamic and 400 kN axial static for this size and a 13.9 kN fatigue load limit Pu. Against a thrust roller bearing of the same 150 mm bore, this bearing is cheaper, quieter and happier at speed, but carries far less load per mm of section. The shaft washer (bore 150 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "For a 150 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 150 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Shock thrust above C0a 400 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51130 stack height of 31 mm and washer set differ from the double-direction execution.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "The Ca 109/C0a 400 kN ratings and 13.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51130; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51130?",
        "a": "51130 is a single-direction thrust ball bearing to ISO 104: 150 mm shaft-washer bore, 190 mm outside diameter, 31 mm stack height (5.906 x 7.48 x 1.22 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 109 kN, C0a 400 kN and a 13.9 kN fatigue load limit Pu; the grease limiting speed is 1,200 r/min and the oil rating 1,800 r/min; mass about 2000 g."
      },
      {
        "q": "How is the 51130 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 30 encodes the 150 mm bore (bore code x 5). The 190 mm OD and 31 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51130 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51130?",
        "a": "At the 1,200 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51130?",
        "a": "The 150/190/31 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 109 kN / C0a 400 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51130-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51130",
      "51130"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51230",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51230",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 150,
    "D_mm": 215,
    "B_mm": 50,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 227,
    "static_load_kN": 720,
    "fatigue_load_limit_kN": 24,
    "limiting_speed_rpm": 900,
    "max_rpm": 900,
    "speed_oil_rpm": 1300,
    "weight_g": 5870,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51230 is an NTN single-direction thrust ball bearing of the medium-section 51200 thrust family: 150 mm bore, 215 mm outside diameter, 50 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. The designation is 512 is the dimension series (medium-section 51200 thrust family) plus 30 encodes the 150 mm bore (bore code x 5). Because the contact points run at 90 deg to the shaft, none of the rating is available for radial load — not even incidentally. Within the thrust-ball plan, 511 is the light section and 514 the heaviest for a given bore; moving up a series raises the C0a from 720 kN class figures at the cost of OD and height. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "For a 150 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 150 mm bore.",
      "The 900 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51230 has no radial capacity at all.",
      "Single-direction means exactly that: thrust on 51230 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The Ca 227/C0a 720 kN ratings and 24 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51230; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51230?",
        "a": "51230 is a single-direction thrust ball bearing to ISO 104: 150 mm shaft-washer bore, 215 mm outside diameter, 50 mm stack height (5.906 x 8.465 x 1.969 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 227 kN, C0a 720 kN and a 24 kN fatigue load limit Pu; the grease limiting speed is 900 r/min and the oil rating 1,300 r/min; mass about 5870 g."
      },
      {
        "q": "How is the 51230 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 30 encodes the 150 mm bore (bore code x 5). The 215 mm OD and 50 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51230 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51230?",
        "a": "At the 900 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51230?",
        "a": "The 150/215/50 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 227 kN / C0a 720 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51230-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51230",
      "51230"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51330",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51330",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 150,
    "D_mm": 250,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 360,
    "static_load_kN": 1130,
    "fatigue_load_limit_kN": 36,
    "limiting_speed_rpm": 660,
    "max_rpm": 660,
    "speed_oil_rpm": 940,
    "weight_g": 16100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51330 belongs to the heavy-section 51300 thrust family of single-direction thrust ball bearings: 150 / 250 / 80 mm (shaft bore / OD / height). NTN builds the number from 513 is the dimension series (heavy-section 51300 thrust family); 30 encodes the 150 mm bore (bore code x 5). Flat-seat washers make the bearing tolerant of simple housings but demand square faces: the whole 360 kN rating assumes the load arrives truly axial. If the duty is high speed with light thrust, check the minimum axial load formula first; a too-large thrust ball bearing fails by skid long before its Ca of 360 kN is ever approached. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "For a 150 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 513 heavy section buys capacity with a larger 250 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 360 kN never saves a bearing that is running too lightly loaded at 660 r/min.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51330 stack height of 80 mm and washer set differ from the double-direction execution.",
      "The Ca 360/C0a 1130 kN ratings and 36 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51330; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51330?",
        "a": "51330 is a single-direction thrust ball bearing to ISO 104: 150 mm shaft-washer bore, 250 mm outside diameter, 80 mm stack height (5.906 x 9.843 x 3.15 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 360 kN, C0a 1130 kN and a 36 kN fatigue load limit Pu; the grease limiting speed is 660 r/min and the oil rating 940 r/min; mass about 16100 g."
      },
      {
        "q": "How is the 51330 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 30 encodes the 150 mm bore (bore code x 5). The 250 mm OD and 80 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51330 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51330?",
        "a": "At the 660 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51330?",
        "a": "The 150/250/80 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 360 kN / C0a 1130 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51330-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 150×250×80 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51330",
      "51330"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51132",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51132",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 160,
    "D_mm": 200,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 112,
    "static_load_kN": 425,
    "fatigue_load_limit_kN": 14.4,
    "limiting_speed_rpm": 1200,
    "max_rpm": 1200,
    "speed_oil_rpm": 1700,
    "weight_g": 2100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51132 is an NTN single-direction thrust ball bearing of the light-section 51100 thrust family: 160 mm bore, 200 mm outside diameter, 31 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. Decoding 51132: 511 is the dimension series (light-section 51100 thrust family), with 32 encodes the 160 mm bore (bore code x 5). The static margin, C0a 425 kN against Ca 112 kN, is what carries slow oscillating or shock thrust without permanent raceway dents. Size selection ends with the minimum-load check: at the 1,200 r/min class speed, the balls need a defined axial preload to keep rolling instead of skidding. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "For a 160 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 160 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 112 kN never saves a bearing that is running too lightly loaded at 1,200 r/min.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51132 has no radial capacity at all.",
      "Shock thrust above C0a 425 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The Ca 112/C0a 425 kN ratings and 14.4 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51132; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51132?",
        "a": "51132 is a single-direction thrust ball bearing to ISO 104: 160 mm shaft-washer bore, 200 mm outside diameter, 31 mm stack height (6.299 x 7.874 x 1.22 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 112 kN, C0a 425 kN and a 14.4 kN fatigue load limit Pu; the grease limiting speed is 1,200 r/min and the oil rating 1,700 r/min; mass about 2100 g."
      },
      {
        "q": "How is the 51132 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 32 encodes the 160 mm bore (bore code x 5). The 200 mm OD and 31 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51132 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51132?",
        "a": "At the 1,200 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51132?",
        "a": "The 160/200/31 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 112 kN / C0a 425 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51132-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51132",
      "51132"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51232",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51232",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 160,
    "D_mm": 225,
    "B_mm": 51,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 223,
    "static_load_kN": 720,
    "fatigue_load_limit_kN": 23.3,
    "limiting_speed_rpm": 870,
    "max_rpm": 870,
    "speed_oil_rpm": 1200,
    "weight_g": 6320,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51232 belongs to the medium-section 51200 thrust family of single-direction thrust ball bearings: 160 / 225 / 51 mm (shaft bore / OD / height). Two fields make up the code — 512 is the dimension series (medium-section 51200 thrust family) and 32 encodes the 160 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 223 kN against C0a 720 kN — a static/dynamic ratio of 3.23 that is the signature of a thrust raceway. Choose the medium-section 51200 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "For a 160 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 160 mm bore.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51232 has no radial capacity at all.",
      "Swapping the shaft and housing washers is an easy assembly error on the 160 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "Swapping the shaft and housing washers is an easy assembly error on the 160 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "The Ca 223/C0a 720 kN ratings and 23.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51232; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51232?",
        "a": "51232 is a single-direction thrust ball bearing to ISO 104: 160 mm shaft-washer bore, 225 mm outside diameter, 51 mm stack height (6.299 x 8.858 x 2.008 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 223 kN, C0a 720 kN and a 23.3 kN fatigue load limit Pu; the grease limiting speed is 870 r/min and the oil rating 1,200 r/min; mass about 6320 g."
      },
      {
        "q": "How is the 51232 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 32 encodes the 160 mm bore (bore code x 5). The 225 mm OD and 51 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51232 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51232?",
        "a": "At the 870 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51232?",
        "a": "The 160/225/51 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 223 kN / C0a 720 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51232-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×225×51 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51232",
      "51232"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51332",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51332",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 160,
    "D_mm": 270,
    "B_mm": 87,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 450,
    "static_load_kN": 1470,
    "fatigue_load_limit_kN": 45,
    "limiting_speed_rpm": 600,
    "max_rpm": 600,
    "speed_oil_rpm": 860,
    "weight_g": 20700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 160 x 270 x 87 mm, NTN 51332 sits in the heavy-section 51300 thrust family of the single-direction thrust programme. Reading the code: 513 is the dimension series (heavy-section 51300 thrust family), and 32 encodes the 160 mm bore (bore code x 5). At 87 mm of height the stack is compact for the 160 mm bore class, trading section height for the heavy-section load level. Within the thrust-ball plan, 511 is the light section and 514 the heaviest for a given bore; moving up a series raises the C0a from 1470 kN class figures at the cost of OD and height. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "For a 160 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 513 heavy section buys capacity with a larger 270 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Single-direction means exactly that: thrust on 51332 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 450 kN never saves a bearing that is running too lightly loaded at 600 r/min.",
      "The Ca 450/C0a 1470 kN ratings and 45 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51332; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51332?",
        "a": "51332 is a single-direction thrust ball bearing to ISO 104: 160 mm shaft-washer bore, 270 mm outside diameter, 87 mm stack height (6.299 x 10.63 x 3.425 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 450 kN, C0a 1470 kN and a 45 kN fatigue load limit Pu; the grease limiting speed is 600 r/min and the oil rating 860 r/min; mass about 20700 g."
      },
      {
        "q": "How is the 51332 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 32 encodes the 160 mm bore (bore code x 5). The 270 mm OD and 87 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51332 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51332?",
        "a": "At the 600 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51332?",
        "a": "The 160/270/87 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 450 kN / C0a 1470 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51332-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 160×270×87 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51332",
      "51332"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51134",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51134",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 170,
    "D_mm": 215,
    "B_mm": 34,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 134,
    "static_load_kN": 510,
    "fatigue_load_limit_kN": 16.7,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1600,
    "weight_g": 2770,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51134 belongs to the light-section 51100 thrust family of single-direction thrust ball bearings: 170 / 215 / 34 mm (shaft bore / OD / height). The designation is 511 is the dimension series (light-section 51100 thrust family) plus 34 encodes the 170 mm bore (bore code x 5). The ball-and-cage set is separable from both washers, which is why the mounting order (shaft washer first, then cage, then housing washer) matters. Selection starts from the load direction: if thrust ever reverses, plan a second thrust bearing (or a double-direction execution) rather than relying on the unloaded raceway. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "For a 170 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 170 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "Swapping the shaft and housing washers is an easy assembly error on the 170 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51134 has no radial capacity at all.",
      "The Ca 134/C0a 510 kN ratings and 16.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51134; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51134?",
        "a": "51134 is a single-direction thrust ball bearing to ISO 104: 170 mm shaft-washer bore, 215 mm outside diameter, 34 mm stack height (6.693 x 8.465 x 1.339 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 134 kN, C0a 510 kN and a 16.7 kN fatigue load limit Pu; the grease limiting speed is 1,100 r/min and the oil rating 1,600 r/min; mass about 2770 g."
      },
      {
        "q": "How is the 51134 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 34 encodes the 170 mm bore (bore code x 5). The 215 mm OD and 34 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51134 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51134?",
        "a": "At the 1,100 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51134?",
        "a": "The 170/215/34 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 134 kN / C0a 510 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51134-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51134",
      "51134"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51234",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51234",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 170,
    "D_mm": 240,
    "B_mm": 55,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 261,
    "static_load_kN": 835,
    "fatigue_load_limit_kN": 26.3,
    "limiting_speed_rpm": 810,
    "max_rpm": 810,
    "speed_oil_rpm": 1200,
    "weight_g": 7810,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 170 x 240 x 55 mm, NTN 51234 sits in the medium-section 51200 thrust family of the single-direction thrust programme. NTN builds the number from 512 is the dimension series (medium-section 51200 thrust family); 34 encodes the 170 mm bore (bore code x 5). NTN prints 261 kN axial dynamic and 835 kN axial static for this size and a 26.3 kN fatigue load limit Pu. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 51234 cannot. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "For a 170 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 170 mm bore.",
      "The C0a of 835 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "The C0a of 835 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "The Ca 261/C0a 835 kN ratings and 26.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51234; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51234?",
        "a": "51234 is a single-direction thrust ball bearing to ISO 104: 170 mm shaft-washer bore, 240 mm outside diameter, 55 mm stack height (6.693 x 9.449 x 2.165 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 261 kN, C0a 835 kN and a 26.3 kN fatigue load limit Pu; the grease limiting speed is 810 r/min and the oil rating 1,200 r/min; mass about 7810 g."
      },
      {
        "q": "How is the 51234 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 34 encodes the 170 mm bore (bore code x 5). The 240 mm OD and 55 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51234 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51234?",
        "a": "At the 810 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51234?",
        "a": "The 170/240/55 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 261 kN / C0a 835 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51234-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 170×240×55 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51234",
      "51234"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51334",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51334",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 170,
    "D_mm": 280,
    "B_mm": 87,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 465,
    "static_load_kN": 1570,
    "fatigue_load_limit_kN": 47.5,
    "limiting_speed_rpm": 590,
    "max_rpm": 590,
    "speed_oil_rpm": 840,
    "weight_g": 21600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the heavy-section 51300 thrust family, 51334 measures 170 mm through the shaft washer, 280 mm over the outside and 87 mm in assembled height. Decoding 51334: 513 is the dimension series (heavy-section 51300 thrust family), with 34 encodes the 170 mm bore (bore code x 5). The washer section here is 55.0 mm of radial height, and the catalogue couples it with Ca 465 kN / C0a 1570 kN. Choose the heavy-section 51300 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "For a 170 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 513 heavy section buys capacity with a larger 280 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "The C0a of 1570 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "The Ca 465/C0a 1570 kN ratings and 47.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51334; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51334?",
        "a": "51334 is a single-direction thrust ball bearing to ISO 104: 170 mm shaft-washer bore, 280 mm outside diameter, 87 mm stack height (6.693 x 11.024 x 3.425 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 465 kN, C0a 1570 kN and a 47.5 kN fatigue load limit Pu; the grease limiting speed is 590 r/min and the oil rating 840 r/min; mass about 21600 g."
      },
      {
        "q": "How is the 51334 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 34 encodes the 170 mm bore (bore code x 5). The 280 mm OD and 87 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51334 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51334?",
        "a": "At the 590 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51334?",
        "a": "The 170/280/87 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 465 kN / C0a 1570 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51334-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 170×280×87 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51334",
      "51334"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51136",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51136",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 180,
    "D_mm": 225,
    "B_mm": 34,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 135,
    "static_load_kN": 525,
    "fatigue_load_limit_kN": 16.7,
    "limiting_speed_rpm": 1100,
    "max_rpm": 1100,
    "speed_oil_rpm": 1500,
    "weight_g": 2920,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 180 x 225 x 34 mm, NTN 51136 sits in the light-section 51100 thrust family of the single-direction thrust programme. Two fields make up the code — 511 is the dimension series (light-section 51100 thrust family) and 36 encodes the 180 mm bore (bore code x 5). With Ca 135 kN and C0a 525 kN, each mm of shaft bore carries about 0.75 kN of dynamic axial rating. The 180/225/34 envelope follows ISO 104, so dimensional interchange holds between makers — raceway osculation and ratings do not automatically follow. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "For a 180 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 180 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51136 stack height of 34 mm and washer set differ from the double-direction execution.",
      "The C0a of 525 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "The Ca 135/C0a 525 kN ratings and 16.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51136; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51136?",
        "a": "51136 is a single-direction thrust ball bearing to ISO 104: 180 mm shaft-washer bore, 225 mm outside diameter, 34 mm stack height (7.087 x 8.858 x 1.339 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 135 kN, C0a 525 kN and a 16.7 kN fatigue load limit Pu; the grease limiting speed is 1,100 r/min and the oil rating 1,500 r/min; mass about 2920 g."
      },
      {
        "q": "How is the 51136 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 36 encodes the 180 mm bore (bore code x 5). The 225 mm OD and 34 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51136 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51136?",
        "a": "At the 1,100 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51136?",
        "a": "The 180/225/34 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 135 kN / C0a 525 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51136-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51136",
      "51136"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51236",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51236",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 180,
    "D_mm": 250,
    "B_mm": 56,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 266,
    "static_load_kN": 875,
    "fatigue_load_limit_kN": 26.9,
    "limiting_speed_rpm": 780,
    "max_rpm": 780,
    "speed_oil_rpm": 1100,
    "weight_g": 8340,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the medium-section 51200 thrust family, 51236 measures 180 mm through the shaft washer, 250 mm over the outside and 56 mm in assembled height. Reading the code: 512 is the dimension series (medium-section 51200 thrust family), and 36 encodes the 180 mm bore (bore code x 5). The static margin, C0a 875 kN against Ca 266 kN, is what carries slow oscillating or shock thrust without permanent raceway dents. Against a thrust roller bearing of the same 180 mm bore, this bearing is cheaper, quieter and happier at speed, but carries far less load per mm of section. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 250 mm OD already tilts the raceway and concentrates the 875 kN static capacity on a few balls. ",
    "applications": [
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "For a 180 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 180 mm bore.",
      "Shock thrust above C0a 875 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "Shock thrust above C0a 875 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The Ca 266/C0a 875 kN ratings and 26.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51236; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51236?",
        "a": "51236 is a single-direction thrust ball bearing to ISO 104: 180 mm shaft-washer bore, 250 mm outside diameter, 56 mm stack height (7.087 x 9.843 x 2.205 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 266 kN, C0a 875 kN and a 26.9 kN fatigue load limit Pu; the grease limiting speed is 780 r/min and the oil rating 1,100 r/min; mass about 8340 g."
      },
      {
        "q": "How is the 51236 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 36 encodes the 180 mm bore (bore code x 5). The 250 mm OD and 56 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51236 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51236?",
        "a": "At the 780 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51236?",
        "a": "The 180/250/56 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 266 kN / C0a 875 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51236-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 180×250×56 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51236",
      "51236"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51336",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51336",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 180,
    "D_mm": 300,
    "B_mm": 95,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 490,
    "static_load_kN": 1700,
    "fatigue_load_limit_kN": 49.5,
    "limiting_speed_rpm": 540,
    "max_rpm": 540,
    "speed_oil_rpm": 780,
    "weight_g": 27500,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51336 appears as a heavy-section 51300 thrust family bearing with a 180 mm shaft washer, a 300 mm housing diameter and 95 mm of stack height. The designation is 513 is the dimension series (heavy-section 51300 thrust family) plus 36 encodes the 180 mm bore (bore code x 5). Catalogue mass is about 27500 g for the full washer-and-cage stack. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 51336 cannot. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 300 mm OD already tilts the raceway and concentrates the 1700 kN static capacity on a few balls. ",
    "applications": [
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "For a 180 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 513 heavy section buys capacity with a larger 300 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "The 540 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "The 540 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "The 540 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "The Ca 490/C0a 1700 kN ratings and 49.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51336; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51336?",
        "a": "51336 is a single-direction thrust ball bearing to ISO 104: 180 mm shaft-washer bore, 300 mm outside diameter, 95 mm stack height (7.087 x 11.811 x 3.74 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 490 kN, C0a 1700 kN and a 49.5 kN fatigue load limit Pu; the grease limiting speed is 540 r/min and the oil rating 780 r/min; mass about 27500 g."
      },
      {
        "q": "How is the 51336 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 36 encodes the 180 mm bore (bore code x 5). The 300 mm OD and 95 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51336 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51336?",
        "a": "At the 540 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51336?",
        "a": "The 180/300/95 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 490 kN / C0a 1700 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51336-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 180×300×95 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51336",
      "51336"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51138",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51138",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 190,
    "D_mm": 240,
    "B_mm": 37,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 170,
    "static_load_kN": 655,
    "fatigue_load_limit_kN": 20.2,
    "limiting_speed_rpm": 980,
    "max_rpm": 980,
    "speed_oil_rpm": 1400,
    "weight_g": 3750,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the light-section 51100 thrust family, 51138 measures 190 mm through the shaft washer, 240 mm over the outside and 37 mm in assembled height. NTN builds the number from 511 is the dimension series (light-section 51100 thrust family); 38 encodes the 190 mm bore (bore code x 5). On speed, the grease limiting speed is 980 r/min and the oil rating 1,400 r/min. For a 190 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "For a 190 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 190 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Swapping the shaft and housing washers is an easy assembly error on the 190 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "The Ca 170/C0a 655 kN ratings and 20.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51138; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51138?",
        "a": "51138 is a single-direction thrust ball bearing to ISO 104: 190 mm shaft-washer bore, 240 mm outside diameter, 37 mm stack height (7.48 x 9.449 x 1.457 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 170 kN, C0a 655 kN and a 20.2 kN fatigue load limit Pu; the grease limiting speed is 980 r/min and the oil rating 1,400 r/min; mass about 3750 g."
      },
      {
        "q": "How is the 51138 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 38 encodes the 190 mm bore (bore code x 5). The 240 mm OD and 37 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51138 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51138?",
        "a": "At the 980 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51138?",
        "a": "The 190/240/37 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 170 kN / C0a 655 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51138-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51138",
      "51138"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51238",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51238",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 190,
    "D_mm": 270,
    "B_mm": 62,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 310,
    "static_load_kN": 1060,
    "fatigue_load_limit_kN": 31.5,
    "limiting_speed_rpm": 710,
    "max_rpm": 710,
    "speed_oil_rpm": 1000,
    "weight_g": 11300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51238 appears as a medium-section 51200 thrust family bearing with a 190 mm shaft washer, a 270 mm housing diameter and 62 mm of stack height. Decoding 51238: 512 is the dimension series (medium-section 51200 thrust family), with 38 encodes the 190 mm bore (bore code x 5). The ball-and-cage set is separable from both washers, which is why the mounting order (shaft washer first, then cage, then housing washer) matters. Size selection ends with the minimum-load check: at the 710 r/min class speed, the balls need a defined axial preload to keep rolling instead of skidding. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot. ",
    "applications": [
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "For a 190 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 190 mm bore.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 310 kN never saves a bearing that is running too lightly loaded at 710 r/min.",
      "Shock thrust above C0a 1060 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51238 has no radial capacity at all.",
      "The Ca 310/C0a 1060 kN ratings and 31.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51238; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51238?",
        "a": "51238 is a single-direction thrust ball bearing to ISO 104: 190 mm shaft-washer bore, 270 mm outside diameter, 62 mm stack height (7.48 x 10.63 x 2.441 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 310 kN, C0a 1060 kN and a 31.5 kN fatigue load limit Pu; the grease limiting speed is 710 r/min and the oil rating 1,000 r/min; mass about 11300 g."
      },
      {
        "q": "How is the 51238 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 38 encodes the 190 mm bore (bore code x 5). The 270 mm OD and 62 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51238 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51238?",
        "a": "At the 710 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51238?",
        "a": "The 190/270/62 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 310 kN / C0a 1060 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51238-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 190×270×62 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51238",
      "51238"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51338",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51338",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 190,
    "D_mm": 320,
    "B_mm": 105,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 545,
    "static_load_kN": 1950,
    "fatigue_load_limit_kN": 55,
    "limiting_speed_rpm": 500,
    "max_rpm": 500,
    "speed_oil_rpm": 710,
    "weight_g": 35000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The heavy-section 51300 thrust family entry 51338 stacks a shaft washer, ball-and-cage set and housing washer into 105 mm of height over a 190 mm bore. Two fields make up the code — 513 is the dimension series (heavy-section 51300 thrust family) and 38 encodes the 190 mm bore (bore code x 5). Because the contact points run at 90 deg to the shaft, none of the rating is available for radial load — not even incidentally. Against a thrust roller bearing of the same 190 mm bore, this bearing is cheaper, quieter and happier at speed, but carries far less load per mm of section. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot. ",
    "applications": [
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "For a 190 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 513 heavy section buys capacity with a larger 320 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51338 has no radial capacity at all.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51338 stack height of 105 mm and washer set differ from the double-direction execution.",
      "Single-direction means exactly that: thrust on 51338 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The Ca 545/C0a 1950 kN ratings and 55 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51338; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51338?",
        "a": "51338 is a single-direction thrust ball bearing to ISO 104: 190 mm shaft-washer bore, 320 mm outside diameter, 105 mm stack height (7.48 x 12.598 x 4.134 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 545 kN, C0a 1950 kN and a 55 kN fatigue load limit Pu; the grease limiting speed is 500 r/min and the oil rating 710 r/min; mass about 35000 g."
      },
      {
        "q": "How is the 51338 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 38 encodes the 190 mm bore (bore code x 5). The 320 mm OD and 105 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51338 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51338?",
        "a": "At the 500 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51338?",
        "a": "The 190/320/105 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 545 kN / C0a 1950 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51338-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 190×320×105 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51338",
      "51338"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51140",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51140",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 200,
    "D_mm": 250,
    "B_mm": 37,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 172,
    "static_load_kN": 675,
    "fatigue_load_limit_kN": 20.4,
    "limiting_speed_rpm": 960,
    "max_rpm": 960,
    "speed_oil_rpm": 1400,
    "weight_g": 3920,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51140 appears as a light-section 51100 thrust family bearing with a 200 mm shaft washer, a 250 mm housing diameter and 37 mm of stack height. Decoding 51140: 511 is the dimension series (light-section 51100 thrust family), with 40 encodes the 200 mm bore (bore code x 5). The static margin, C0a 675 kN against Ca 172 kN, is what carries slow oscillating or shock thrust without permanent raceway dents. Selection starts from the load direction: if thrust ever reverses, plan a second thrust bearing (or a double-direction execution) rather than relying on the unloaded raceway. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting"
    ],
    "pitfalls": [
      "For a 200 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 200 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "Shock thrust above C0a 675 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Shock thrust above C0a 675 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The Ca 172/C0a 675 kN ratings and 20.4 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51140; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51140?",
        "a": "51140 is a single-direction thrust ball bearing to ISO 104: 200 mm shaft-washer bore, 250 mm outside diameter, 37 mm stack height (7.874 x 9.843 x 1.457 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 172 kN, C0a 675 kN and a 20.4 kN fatigue load limit Pu; the grease limiting speed is 960 r/min and the oil rating 1,400 r/min; mass about 3920 g."
      },
      {
        "q": "How is the 51140 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 40 encodes the 200 mm bore (bore code x 5). The 250 mm OD and 37 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51140 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51140?",
        "a": "At the 960 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51140?",
        "a": "The 200/250/37 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 172 kN / C0a 675 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51140-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51140",
      "51140"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51240",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51240",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 200,
    "D_mm": 280,
    "B_mm": 62,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 315,
    "static_load_kN": 1110,
    "fatigue_load_limit_kN": 32,
    "limiting_speed_rpm": 700,
    "max_rpm": 700,
    "speed_oil_rpm": 990,
    "weight_g": 11800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The medium-section 51200 thrust family entry 51240 stacks a shaft washer, ball-and-cage set and housing washer into 62 mm of height over a 200 mm bore. Two fields make up the code — 512 is the dimension series (medium-section 51200 thrust family) and 40 encodes the 200 mm bore (bore code x 5). Catalogue axial dynamic rating Ca is 315 kN against C0a 1110 kN — a static/dynamic ratio of 3.52 that is the signature of a thrust raceway. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 51240 cannot. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 280 mm OD already tilts the raceway and concentrates the 1110 kN static capacity on a few balls. ",
    "applications": [
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "For a 200 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 200 mm bore.",
      "The C0a of 1110 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Single-direction means exactly that: thrust on 51240 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Swapping the shaft and housing washers is an easy assembly error on the 200 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "The Ca 315/C0a 1110 kN ratings and 32 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51240; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51240?",
        "a": "51240 is a single-direction thrust ball bearing to ISO 104: 200 mm shaft-washer bore, 280 mm outside diameter, 62 mm stack height (7.874 x 11.024 x 2.441 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 315 kN, C0a 1110 kN and a 32 kN fatigue load limit Pu; the grease limiting speed is 700 r/min and the oil rating 990 r/min; mass about 11800 g."
      },
      {
        "q": "How is the 51240 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 40 encodes the 200 mm bore (bore code x 5). The 280 mm OD and 62 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51240 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51240?",
        "a": "At the 700 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51240?",
        "a": "The 200/280/62 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 315 kN / C0a 1110 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51240-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 200×280×62 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51240",
      "51240"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51340",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51340",
    "series": "51300-series",
    "type": "thrust_ball",
    "d_mm": 200,
    "D_mm": 340,
    "B_mm": 110,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 595,
    "static_load_kN": 2220,
    "fatigue_load_limit_kN": 61,
    "limiting_speed_rpm": 470,
    "max_rpm": 470,
    "speed_oil_rpm": 670,
    "weight_g": 41800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51340 is the 200 mm member of NTN's heavy-section 51300 thrust family: 340 mm across the washers, 110 mm tall. Reading the code: 513 is the dimension series (heavy-section 51300 thrust family), and 40 encodes the 200 mm bore (bore code x 5). At 110 mm of height the stack is compact for the 200 mm bore class, trading section height for the heavy-section load level. Choose the heavy-section 51300 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 340 mm OD already tilts the raceway and concentrates the 2220 kN static capacity on a few balls. ",
    "applications": [
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "For a 200 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 513 heavy section buys capacity with a larger 340 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51340 has no radial capacity at all.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 595 kN never saves a bearing that is running too lightly loaded at 470 r/min.",
      "The Ca 595/C0a 2220 kN ratings and 61 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51340; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51340?",
        "a": "51340 is a single-direction thrust ball bearing to ISO 104: 200 mm shaft-washer bore, 340 mm outside diameter, 110 mm stack height (7.874 x 13.386 x 4.331 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 595 kN, C0a 2220 kN and a 61 kN fatigue load limit Pu; the grease limiting speed is 470 r/min and the oil rating 670 r/min; mass about 41800 g."
      },
      {
        "q": "How is the 51340 designation structured?",
        "a": "513 is the dimension series (heavy-section 51300 thrust family); 40 encodes the 200 mm bore (bore code x 5). The 340 mm OD and 110 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51340 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51340?",
        "a": "At the 470 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51340?",
        "a": "The 200/340/110 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 595 kN / C0a 2220 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51340-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 200×340×110 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51340",
      "51340"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51144",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51144",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 220,
    "D_mm": 270,
    "B_mm": 37,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 177,
    "static_load_kN": 740,
    "fatigue_load_limit_kN": 21.3,
    "limiting_speed_rpm": 920,
    "max_rpm": 920,
    "speed_oil_rpm": 1300,
    "weight_g": 4270,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51144 is the 220 mm member of NTN's light-section 51100 thrust family: 270 mm across the washers, 37 mm tall. Two fields make up the code — 511 is the dimension series (light-section 51100 thrust family) and 44 encodes the 220 mm bore (bore code x 5). With Ca 177 kN and C0a 740 kN, each mm of shaft bore carries about 0.80 kN of dynamic axial rating. For a 220 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 270 mm OD already tilts the raceway and concentrates the 740 kN static capacity on a few balls. ",
    "applications": [
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "For a 220 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 220 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Swapping the shaft and housing washers is an easy assembly error on the 220 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 177 kN never saves a bearing that is running too lightly loaded at 920 r/min.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "The Ca 177/C0a 740 kN ratings and 21.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51144; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51144?",
        "a": "51144 is a single-direction thrust ball bearing to ISO 104: 220 mm shaft-washer bore, 270 mm outside diameter, 37 mm stack height (8.661 x 10.63 x 1.457 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 177 kN, C0a 740 kN and a 21.3 kN fatigue load limit Pu; the grease limiting speed is 920 r/min and the oil rating 1,300 r/min; mass about 4270 g."
      },
      {
        "q": "How is the 51144 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 44 encodes the 220 mm bore (bore code x 5). The 270 mm OD and 37 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51144 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51144?",
        "a": "At the 920 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51144?",
        "a": "The 220/270/37 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 177 kN / C0a 740 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51144-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51144",
      "51144"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51244",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51244",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 220,
    "D_mm": 300,
    "B_mm": 63,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 325,
    "static_load_kN": 1210,
    "fatigue_load_limit_kN": 34,
    "limiting_speed_rpm": 660,
    "max_rpm": 660,
    "speed_oil_rpm": 950,
    "weight_g": 13000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51244 is an NTN single-direction thrust ball bearing of the medium-section 51200 thrust family: 220 mm bore, 300 mm outside diameter, 63 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. Reading the code: 512 is the dimension series (medium-section 51200 thrust family), and 44 encodes the 220 mm bore (bore code x 5). The static margin, C0a 1210 kN against Ca 325 kN, is what carries slow oscillating or shock thrust without permanent raceway dents. Size selection ends with the minimum-load check: at the 660 r/min class speed, the balls need a defined axial preload to keep rolling instead of skidding. The shaft washer (bore 220 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "For a 220 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 220 mm bore.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 325 kN never saves a bearing that is running too lightly loaded at 660 r/min.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Shock thrust above C0a 1210 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The Ca 325/C0a 1210 kN ratings and 34 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51244; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51244?",
        "a": "51244 is a single-direction thrust ball bearing to ISO 104: 220 mm shaft-washer bore, 300 mm outside diameter, 63 mm stack height (8.661 x 11.811 x 2.48 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 325 kN, C0a 1210 kN and a 34 kN fatigue load limit Pu; the grease limiting speed is 660 r/min and the oil rating 950 r/min; mass about 13000 g."
      },
      {
        "q": "How is the 51244 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 44 encodes the 220 mm bore (bore code x 5). The 300 mm OD and 63 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51244 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51244?",
        "a": "At the 660 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51244?",
        "a": "The 220/300/63 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 325 kN / C0a 1210 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51244-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 220×300×63 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51244",
      "51244"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51148",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51148",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 240,
    "D_mm": 300,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 228,
    "static_load_kN": 935,
    "fatigue_load_limit_kN": 25.6,
    "limiting_speed_rpm": 780,
    "max_rpm": 780,
    "speed_oil_rpm": 1100,
    "weight_g": 6870,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51148 belongs to the light-section 51100 thrust family of single-direction thrust ball bearings: 240 / 300 / 45 mm (shaft bore / OD / height). Reading the code: 511 is the dimension series (light-section 51100 thrust family), and 48 encodes the 240 mm bore (bore code x 5). Flat-seat washers make the bearing tolerant of simple housings but demand square faces: the whole 228 kN rating assumes the load arrives truly axial. Within the thrust-ball plan, 511 is the light section and 514 the heaviest for a given bore; moving up a series raises the C0a from 935 kN class figures at the cost of OD and height. The shaft washer (bore 240 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "For a 240 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 240 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Single-direction means exactly that: thrust on 51148 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51148 stack height of 45 mm and washer set differ from the double-direction execution.",
      "The Ca 228/C0a 935 kN ratings and 25.6 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51148; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51148?",
        "a": "51148 is a single-direction thrust ball bearing to ISO 104: 240 mm shaft-washer bore, 300 mm outside diameter, 45 mm stack height (9.449 x 11.811 x 1.772 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 228 kN, C0a 935 kN and a 25.6 kN fatigue load limit Pu; the grease limiting speed is 780 r/min and the oil rating 1,100 r/min; mass about 6870 g."
      },
      {
        "q": "How is the 51148 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 48 encodes the 240 mm bore (bore code x 5). The 300 mm OD and 45 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51148 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51148?",
        "a": "At the 780 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51148?",
        "a": "The 240/300/45 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 228 kN / C0a 935 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51148-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 240×300×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51148",
      "51148"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51248",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51248",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 240,
    "D_mm": 340,
    "B_mm": 78,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 415,
    "static_load_kN": 1650,
    "fatigue_load_limit_kN": 44,
    "limiting_speed_rpm": 550,
    "max_rpm": 550,
    "speed_oil_rpm": 790,
    "weight_g": 22400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 240 x 340 x 78 mm, NTN 51248 sits in the medium-section 51200 thrust family of the single-direction thrust programme. The designation is 512 is the dimension series (medium-section 51200 thrust family) plus 48 encodes the 240 mm bore (bore code x 5). With Ca 415 kN and C0a 1650 kN, each mm of shaft bore carries about 1.73 kN of dynamic axial rating. The 240/340/78 envelope follows ISO 104, so dimensional interchange holds between makers — raceway osculation and ratings do not automatically follow. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "For a 240 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 240 mm bore.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51248 stack height of 78 mm and washer set differ from the double-direction execution.",
      "The 550 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "The Ca 415/C0a 1650 kN ratings and 44 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51248; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51248?",
        "a": "51248 is a single-direction thrust ball bearing to ISO 104: 240 mm shaft-washer bore, 340 mm outside diameter, 78 mm stack height (9.449 x 13.386 x 3.071 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 415 kN, C0a 1650 kN and a 44 kN fatigue load limit Pu; the grease limiting speed is 550 r/min and the oil rating 790 r/min; mass about 22400 g."
      },
      {
        "q": "How is the 51248 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 48 encodes the 240 mm bore (bore code x 5). The 340 mm OD and 78 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51248 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51248?",
        "a": "At the 550 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51248?",
        "a": "The 240/340/78 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 415 kN / C0a 1650 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51248-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 240×340×78 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51248",
      "51248"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51152",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51152",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 260,
    "D_mm": 320,
    "B_mm": 45,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 232,
    "static_load_kN": 990,
    "fatigue_load_limit_kN": 26.2,
    "limiting_speed_rpm": 750,
    "max_rpm": 750,
    "speed_oil_rpm": 1100,
    "weight_g": 7380,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the light-section 51100 thrust family, 51152 measures 260 mm through the shaft washer, 320 mm over the outside and 45 mm in assembled height. Two fields make up the code — 511 is the dimension series (light-section 51100 thrust family) and 52 encodes the 260 mm bore (bore code x 5). With Ca 232 kN and C0a 990 kN, each mm of shaft bore carries about 0.89 kN of dynamic axial rating. If the duty is high speed with light thrust, check the minimum axial load formula first; a too-large thrust ball bearing fails by skid long before its Ca of 232 kN is ever approached. The shaft washer (bore 260 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "For a 260 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 260 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51152 stack height of 45 mm and washer set differ from the double-direction execution.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "The Ca 232/C0a 990 kN ratings and 26.2 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51152; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51152?",
        "a": "51152 is a single-direction thrust ball bearing to ISO 104: 260 mm shaft-washer bore, 320 mm outside diameter, 45 mm stack height (10.236 x 12.598 x 1.772 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 232 kN, C0a 990 kN and a 26.2 kN fatigue load limit Pu; the grease limiting speed is 750 r/min and the oil rating 1,100 r/min; mass about 7380 g."
      },
      {
        "q": "How is the 51152 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 52 encodes the 260 mm bore (bore code x 5). The 320 mm OD and 45 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51152 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51152?",
        "a": "At the 750 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51152?",
        "a": "The 260/320/45 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 232 kN / C0a 990 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51152-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51152",
      "51152"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51252",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51252",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 260,
    "D_mm": 360,
    "B_mm": 79,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 440,
    "static_load_kN": 1810,
    "fatigue_load_limit_kN": 46.5,
    "limiting_speed_rpm": 530,
    "max_rpm": 530,
    "speed_oil_rpm": 760,
    "weight_g": 24200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51252 appears as a medium-section 51200 thrust family bearing with a 260 mm shaft washer, a 360 mm housing diameter and 79 mm of stack height. Reading the code: 512 is the dimension series (medium-section 51200 thrust family), and 52 encodes the 260 mm bore (bore code x 5). The static margin, C0a 1810 kN against Ca 440 kN, is what carries slow oscillating or shock thrust without permanent raceway dents. Selection starts from the load direction: if thrust ever reverses, plan a second thrust bearing (or a double-direction execution) rather than relying on the unloaded raceway. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "For a 260 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 260 mm bore.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51252 has no radial capacity at all.",
      "Shock thrust above C0a 1810 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The Ca 440/C0a 1810 kN ratings and 46.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51252; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51252?",
        "a": "51252 is a single-direction thrust ball bearing to ISO 104: 260 mm shaft-washer bore, 360 mm outside diameter, 79 mm stack height (10.236 x 14.173 x 3.11 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 440 kN, C0a 1810 kN and a 46.5 kN fatigue load limit Pu; the grease limiting speed is 530 r/min and the oil rating 760 r/min; mass about 24200 g."
      },
      {
        "q": "How is the 51252 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 52 encodes the 260 mm bore (bore code x 5). The 360 mm OD and 79 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51252 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51252?",
        "a": "At the 530 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51252?",
        "a": "The 260/360/79 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 440 kN / C0a 1810 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51252-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 260×360×79 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51252",
      "51252"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51156",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51156",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 280,
    "D_mm": 350,
    "B_mm": 53,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 305,
    "static_load_kN": 1270,
    "fatigue_load_limit_kN": 32.5,
    "limiting_speed_rpm": 650,
    "max_rpm": 650,
    "speed_oil_rpm": 940,
    "weight_g": 11800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The light-section 51100 thrust family entry 51156 stacks a shaft washer, ball-and-cage set and housing washer into 53 mm of height over a 280 mm bore. Reading the code: 511 is the dimension series (light-section 51100 thrust family), and 56 encodes the 280 mm bore (bore code x 5). Flat-seat washers make the bearing tolerant of simple housings but demand square faces: the whole 305 kN rating assumes the load arrives truly axial. Choose the light-section 51100 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "For a 280 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 280 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Swapping the shaft and housing washers is an easy assembly error on the 280 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51156 stack height of 53 mm and washer set differ from the double-direction execution.",
      "The Ca 305/C0a 1270 kN ratings and 32.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51156; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51156?",
        "a": "51156 is a single-direction thrust ball bearing to ISO 104: 280 mm shaft-washer bore, 350 mm outside diameter, 53 mm stack height (11.024 x 13.78 x 2.087 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 305 kN, C0a 1270 kN and a 32.5 kN fatigue load limit Pu; the grease limiting speed is 650 r/min and the oil rating 940 r/min; mass about 11800 g."
      },
      {
        "q": "How is the 51156 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 56 encodes the 280 mm bore (bore code x 5). The 350 mm OD and 53 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51156 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51156?",
        "a": "At the 650 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51156?",
        "a": "The 280/350/53 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 305 kN / C0a 1270 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51156-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 280×350×53 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51156",
      "51156"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51256",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51256",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 280,
    "D_mm": 380,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 460,
    "static_load_kN": 1970,
    "fatigue_load_limit_kN": 49,
    "limiting_speed_rpm": 510,
    "max_rpm": 510,
    "speed_oil_rpm": 730,
    "weight_g": 26100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51256 is the 280 mm member of NTN's medium-section 51200 thrust family: 380 mm across the washers, 80 mm tall. The designation is 512 is the dimension series (medium-section 51200 thrust family) plus 56 encodes the 280 mm bore (bore code x 5). With Ca 460 kN and C0a 1970 kN, each mm of shaft bore carries about 1.64 kN of dynamic axial rating. For a 280 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "For a 280 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 280 mm bore.",
      "Swapping the shaft and housing washers is an easy assembly error on the 280 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "The C0a of 1970 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "The Ca 460/C0a 1970 kN ratings and 49 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51256; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51256?",
        "a": "51256 is a single-direction thrust ball bearing to ISO 104: 280 mm shaft-washer bore, 380 mm outside diameter, 80 mm stack height (11.024 x 14.961 x 3.15 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 460 kN, C0a 1970 kN and a 49 kN fatigue load limit Pu; the grease limiting speed is 510 r/min and the oil rating 730 r/min; mass about 26100 g."
      },
      {
        "q": "How is the 51256 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 56 encodes the 280 mm bore (bore code x 5). The 380 mm OD and 80 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51256 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51256?",
        "a": "At the 510 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51256?",
        "a": "The 280/380/80 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 460 kN / C0a 1970 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51256-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 280×380×80 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51256",
      "51256"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51160",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51160",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 300,
    "D_mm": 380,
    "B_mm": 62,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 355,
    "static_load_kN": 1560,
    "fatigue_load_limit_kN": 38,
    "limiting_speed_rpm": 580,
    "max_rpm": 580,
    "speed_oil_rpm": 820,
    "weight_g": 17200,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51160 is an NTN single-direction thrust ball bearing of the light-section 51100 thrust family: 300 mm bore, 380 mm outside diameter, 62 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. Two fields make up the code — 511 is the dimension series (light-section 51100 thrust family) and 60 encodes the 300 mm bore (bore code x 5). Flat-seat washers make the bearing tolerant of simple housings but demand square faces: the whole 355 kN rating assumes the load arrives truly axial. For a 300 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges"
    ],
    "pitfalls": [
      "For a 300 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 300 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Single-direction means exactly that: thrust on 51160 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The 580 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51160 stack height of 62 mm and washer set differ from the double-direction execution.",
      "The Ca 355/C0a 1560 kN ratings and 38 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51160; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51160?",
        "a": "51160 is a single-direction thrust ball bearing to ISO 104: 300 mm shaft-washer bore, 380 mm outside diameter, 62 mm stack height (11.811 x 14.961 x 2.441 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 355 kN, C0a 1560 kN and a 38 kN fatigue load limit Pu; the grease limiting speed is 580 r/min and the oil rating 820 r/min; mass about 17200 g."
      },
      {
        "q": "How is the 51160 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 60 encodes the 300 mm bore (bore code x 5). The 380 mm OD and 62 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51160 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51160?",
        "a": "At the 580 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51160?",
        "a": "The 300/380/62 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 355 kN / C0a 1560 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51160-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 300×380×62 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51160",
      "51160"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51260",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51260",
    "series": "51200-series",
    "type": "thrust_ball",
    "d_mm": 300,
    "D_mm": 420,
    "B_mm": 95,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 590,
    "static_load_kN": 2680,
    "fatigue_load_limit_kN": 63.5,
    "limiting_speed_rpm": 440,
    "max_rpm": 440,
    "speed_oil_rpm": 630,
    "weight_g": 40600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51260 belongs to the medium-section 51200 thrust family of single-direction thrust ball bearings: 300 / 420 / 95 mm (shaft bore / OD / height). Reading the code: 512 is the dimension series (medium-section 51200 thrust family), and 60 encodes the 300 mm bore (bore code x 5). The static margin, C0a 2680 kN against Ca 590 kN, is what carries slow oscillating or shock thrust without permanent raceway dents. The 300/420/95 envelope follows ISO 104, so dimensional interchange holds between makers — raceway osculation and ratings do not automatically follow. The housing washer needs radial freedom in its seat so the bearing can centre itself; clamping it radially defeats the self-centring the loose fit is designed to give. ",
    "applications": [
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "For a 300 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 300 mm bore.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51260 stack height of 95 mm and washer set differ from the double-direction execution.",
      "Shock thrust above C0a 2680 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Shock thrust above C0a 2680 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The Ca 590/C0a 2680 kN ratings and 63.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51260; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51260?",
        "a": "51260 is a single-direction thrust ball bearing to ISO 104: 300 mm shaft-washer bore, 420 mm outside diameter, 95 mm stack height (11.811 x 16.535 x 3.74 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 590 kN, C0a 2680 kN and a 63.5 kN fatigue load limit Pu; the grease limiting speed is 440 r/min and the oil rating 630 r/min; mass about 40600 g."
      },
      {
        "q": "How is the 51260 designation structured?",
        "a": "512 is the dimension series (medium-section 51200 thrust family); 60 encodes the 300 mm bore (bore code x 5). The 420 mm OD and 95 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51260 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51260?",
        "a": "At the 440 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51260?",
        "a": "The 300/420/95 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 590 kN / C0a 2680 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51260-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 300×420×95 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51260",
      "51260"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51164",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51164",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 320,
    "D_mm": 400,
    "B_mm": 63,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 365,
    "static_load_kN": 1660,
    "fatigue_load_limit_kN": 39.5,
    "limiting_speed_rpm": 550,
    "max_rpm": 550,
    "speed_oil_rpm": 790,
    "weight_g": 18400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 320 x 400 x 63 mm, NTN 51164 sits in the light-section 51100 thrust family of the single-direction thrust programme. Reading the code: 511 is the dimension series (light-section 51100 thrust family), and 64 encodes the 320 mm bore (bore code x 5). The washer section here is 40.0 mm of radial height, and the catalogue couples it with Ca 365 kN / C0a 1660 kN. Within the thrust-ball plan, 511 is the light section and 514 the heaviest for a given bore; moving up a series raises the C0a from 1660 kN class figures at the cost of OD and height. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot. ",
    "applications": [
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "For a 320 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 320 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "The 550 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51164 has no radial capacity at all.",
      "The C0a of 1660 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "The Ca 365/C0a 1660 kN ratings and 39.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51164; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51164?",
        "a": "51164 is a single-direction thrust ball bearing to ISO 104: 320 mm shaft-washer bore, 400 mm outside diameter, 63 mm stack height (12.598 x 15.748 x 2.48 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 365 kN, C0a 1660 kN and a 39.5 kN fatigue load limit Pu; the grease limiting speed is 550 r/min and the oil rating 790 r/min; mass about 18400 g."
      },
      {
        "q": "How is the 51164 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 64 encodes the 320 mm bore (bore code x 5). The 400 mm OD and 63 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51164 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51164?",
        "a": "At the 550 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51164?",
        "a": "The 320/400/63 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 365 kN / C0a 1660 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51164-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 320×400×63 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51164",
      "51164"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51168",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51168",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 340,
    "D_mm": 420,
    "B_mm": 64,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 375,
    "static_load_kN": 1760,
    "fatigue_load_limit_kN": 40.5,
    "limiting_speed_rpm": 530,
    "max_rpm": 530,
    "speed_oil_rpm": 760,
    "weight_g": 19700,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51168 appears as a light-section 51100 thrust family bearing with a 340 mm shaft washer, a 420 mm housing diameter and 64 mm of stack height. The designation is 511 is the dimension series (light-section 51100 thrust family) plus 68 encodes the 340 mm bore (bore code x 5). Because the contact points run at 90 deg to the shaft, none of the rating is available for radial load — not even incidentally. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 51168 cannot. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "For a 340 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 340 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "The C0a of 1760 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "The C0a of 1760 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Single-direction means exactly that: thrust on 51168 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The Ca 375/C0a 1760 kN ratings and 40.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51168; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51168?",
        "a": "51168 is a single-direction thrust ball bearing to ISO 104: 340 mm shaft-washer bore, 420 mm outside diameter, 64 mm stack height (13.386 x 16.535 x 2.52 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 375 kN, C0a 1760 kN and a 40.5 kN fatigue load limit Pu; the grease limiting speed is 530 r/min and the oil rating 760 r/min; mass about 19700 g."
      },
      {
        "q": "How is the 51168 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 68 encodes the 340 mm bore (bore code x 5). The 420 mm OD and 64 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51168 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51168?",
        "a": "At the 530 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51168?",
        "a": "The 340/420/64 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 375 kN / C0a 1760 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51168-M",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 340×420×64 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51168",
      "51168"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51172",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51172",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 360,
    "D_mm": 440,
    "B_mm": 65,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 380,
    "static_load_kN": 1860,
    "fatigue_load_limit_kN": 42,
    "limiting_speed_rpm": 510,
    "max_rpm": 510,
    "speed_oil_rpm": 730,
    "weight_g": 21100,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51172 is the 360 mm member of NTN's light-section 51100 thrust family: 440 mm across the washers, 65 mm tall. Reading the code: 511 is the dimension series (light-section 51100 thrust family), and 72 encodes the 360 mm bore (bore code x 5). The washer section here is 40.0 mm of radial height, and the catalogue couples it with Ca 380 kN / C0a 1860 kN. Choose the light-section 51100 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. Preload or working clearance must guarantee the minimum axial load at the catalogue speed; a spring or dead-weight arrangement is the usual answer on high-speed vertical shafts. ",
    "applications": [
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "For a 360 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 360 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51172 has no radial capacity at all.",
      "Shock thrust above C0a 1860 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "The C0a of 1860 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "The Ca 380/C0a 1860 kN ratings and 42 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51172; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51172?",
        "a": "51172 is a single-direction thrust ball bearing to ISO 104: 360 mm shaft-washer bore, 440 mm outside diameter, 65 mm stack height (14.173 x 17.323 x 2.559 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 380 kN, C0a 1860 kN and a 42 kN fatigue load limit Pu; the grease limiting speed is 510 r/min and the oil rating 730 r/min; mass about 21100 g."
      },
      {
        "q": "How is the 51172 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 72 encodes the 360 mm bore (bore code x 5). The 440 mm OD and 65 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51172 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51172?",
        "a": "At the 510 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51172?",
        "a": "The 360/440/65 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 380 kN / C0a 1860 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51172-F",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 360×440×65 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51172",
      "51172"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51176",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51176",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 380,
    "D_mm": 460,
    "B_mm": 65,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 380,
    "static_load_kN": 1910,
    "fatigue_load_limit_kN": 42,
    "limiting_speed_rpm": 500,
    "max_rpm": 500,
    "speed_oil_rpm": 710,
    "weight_g": 22300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 51176 belongs to the light-section 51100 thrust family of single-direction thrust ball bearings: 380 / 460 / 65 mm (shaft bore / OD / height). The designation is 511 is the dimension series (light-section 51100 thrust family) plus 76 encodes the 380 mm bore (bore code x 5). Because the contact points run at 90 deg to the shaft, none of the rating is available for radial load — not even incidentally. Against a thrust roller bearing of the same 380 mm bore, this bearing is cheaper, quieter and happier at speed, but carries far less load per mm of section. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "For a 380 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 380 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Shock thrust above C0a 1910 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 380 kN never saves a bearing that is running too lightly loaded at 500 r/min.",
      "Single-direction means exactly that: thrust on 51176 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The Ca 380/C0a 1910 kN ratings and 42 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51176; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51176?",
        "a": "51176 is a single-direction thrust ball bearing to ISO 104: 380 mm shaft-washer bore, 460 mm outside diameter, 65 mm stack height (14.961 x 18.11 x 2.559 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 380 kN, C0a 1910 kN and a 42 kN fatigue load limit Pu; the grease limiting speed is 500 r/min and the oil rating 710 r/min; mass about 22300 g."
      },
      {
        "q": "How is the 51176 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 76 encodes the 380 mm bore (bore code x 5). The 460 mm OD and 65 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51176 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51176?",
        "a": "At the 500 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51176?",
        "a": "The 380/460/65 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 380 kN / C0a 1910 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51176-F",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 380×460×65 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51176",
      "51176"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51180",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51180",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 400,
    "D_mm": 480,
    "B_mm": 65,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 390,
    "static_load_kN": 2010,
    "fatigue_load_limit_kN": 43.5,
    "limiting_speed_rpm": 480,
    "max_rpm": 480,
    "speed_oil_rpm": 690,
    "weight_g": 23300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "From the light-section 51100 thrust family, 51180 measures 400 mm through the shaft washer, 480 mm over the outside and 65 mm in assembled height. Reading the code: 511 is the dimension series (light-section 51100 thrust family), and 80 encodes the 400 mm bore (bore code x 5). The washer section here is 40.0 mm of radial height, and the catalogue couples it with Ca 390 kN / C0a 2010 kN. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 51180 cannot. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "For a 400 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 400 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "The C0a of 2010 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "The C0a of 2010 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.",
      "The Ca 390/C0a 2010 kN ratings and 43.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51180; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51180?",
        "a": "51180 is a single-direction thrust ball bearing to ISO 104: 400 mm shaft-washer bore, 480 mm outside diameter, 65 mm stack height (15.748 x 18.898 x 2.559 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 390 kN, C0a 2010 kN and a 43.5 kN fatigue load limit Pu; the grease limiting speed is 480 r/min and the oil rating 690 r/min; mass about 23300 g."
      },
      {
        "q": "How is the 51180 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 80 encodes the 400 mm bore (bore code x 5). The 480 mm OD and 65 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51180 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51180?",
        "a": "At the 480 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51180?",
        "a": "The 400/480/65 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 390 kN / C0a 2010 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51180-F",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 400×480×65 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51180",
      "51180"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51184",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51184",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 420,
    "D_mm": 500,
    "B_mm": 65,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 395,
    "static_load_kN": 2110,
    "fatigue_load_limit_kN": 44.5,
    "limiting_speed_rpm": 470,
    "max_rpm": 470,
    "speed_oil_rpm": 670,
    "weight_g": 24400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "The light-section 51100 thrust family entry 51184 stacks a shaft washer, ball-and-cage set and housing washer into 65 mm of height over a 420 mm bore. The designation is 511 is the dimension series (light-section 51100 thrust family) plus 84 encodes the 420 mm bore (bore code x 5). Because the contact points run at 90 deg to the shaft, none of the rating is available for radial load — not even incidentally. Size selection ends with the minimum-load check: at the 470 r/min class speed, the balls need a defined axial preload to keep rolling instead of skidding. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 500 mm OD already tilts the raceway and concentrates the 2110 kN static capacity on a few balls. ",
    "applications": [
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "For a 420 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 420 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Below the minimum axial load the balls skid; the catalogue Ca of 395 kN never saves a bearing that is running too lightly loaded at 470 r/min.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51184 stack height of 65 mm and washer set differ from the double-direction execution.",
      "Single-direction means exactly that: thrust on 51184 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The Ca 395/C0a 2110 kN ratings and 44.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51184; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51184?",
        "a": "51184 is a single-direction thrust ball bearing to ISO 104: 420 mm shaft-washer bore, 500 mm outside diameter, 65 mm stack height (16.535 x 19.685 x 2.559 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 395 kN, C0a 2110 kN and a 44.5 kN fatigue load limit Pu; the grease limiting speed is 470 r/min and the oil rating 670 r/min; mass about 24400 g."
      },
      {
        "q": "How is the 51184 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 84 encodes the 420 mm bore (bore code x 5). The 500 mm OD and 65 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51184 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51184?",
        "a": "At the 470 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51184?",
        "a": "The 420/500/65 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 395 kN / C0a 2110 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51184-F",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 420×500×65 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51184",
      "51184"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51188",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51188",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 440,
    "D_mm": 540,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 515,
    "static_load_kN": 2850,
    "fatigue_load_limit_kN": 58,
    "limiting_speed_rpm": 400,
    "max_rpm": 400,
    "speed_oil_rpm": 580,
    "weight_g": 40000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "51188 is an NTN single-direction thrust ball bearing of the light-section 51100 thrust family: 440 mm bore, 540 mm outside diameter, 80 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. NTN builds the number from 511 is the dimension series (light-section 51100 thrust family); 88 encodes the 440 mm bore (bore code x 5). NTN prints 515 kN axial dynamic and 2850 kN axial static for this size and a 58 kN fatigue load limit Pu. The 440/540/80 envelope follows ISO 104, so dimensional interchange holds between makers — raceway osculation and ratings do not automatically follow. The shaft washer (bore 440 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts",
      "heavy press and mill screwdown thrust seats"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "For a 440 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 440 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Never substitute a double-direction bearing drawing part-for-part: the single-direction 51188 stack height of 80 mm and washer set differ from the double-direction execution.",
      "Swapping the shaft and housing washers is an easy assembly error on the 440 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "The Ca 515/C0a 2850 kN ratings and 58 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51188; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51188?",
        "a": "51188 is a single-direction thrust ball bearing to ISO 104: 440 mm shaft-washer bore, 540 mm outside diameter, 80 mm stack height (17.323 x 21.26 x 3.15 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 515 kN, C0a 2850 kN and a 58 kN fatigue load limit Pu; the grease limiting speed is 400 r/min and the oil rating 580 r/min; mass about 40000 g."
      },
      {
        "q": "How is the 51188 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 88 encodes the 440 mm bore (bore code x 5). The 540 mm OD and 80 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51188 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51188?",
        "a": "At the 400 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51188?",
        "a": "The 440/540/80 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 515 kN / C0a 2850 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51188-F",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 440×540×80 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51188",
      "51188"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51192",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51192",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 460,
    "D_mm": 560,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 525,
    "static_load_kN": 3000,
    "fatigue_load_limit_kN": 60,
    "limiting_speed_rpm": 390,
    "max_rpm": 390,
    "speed_oil_rpm": 560,
    "weight_g": 41600,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 460 x 560 x 80 mm, NTN 51192 sits in the light-section 51100 thrust family of the single-direction thrust programme. The designation is 511 is the dimension series (light-section 51100 thrust family) plus 92 encodes the 460 mm bore (bore code x 5). Because the contact points run at 90 deg to the shaft, none of the rating is available for radial load — not even incidentally. Selection starts from the load direction: if thrust ever reverses, plan a second thrust bearing (or a double-direction execution) rather than relying on the unloaded raceway. The shaft washer (bore 460 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on. ",
    "applications": [
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "For a 460 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 460 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.",
      "Single-direction means exactly that: thrust on 51192 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "The Ca 525/C0a 3000 kN ratings and 60 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51192; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51192?",
        "a": "51192 is a single-direction thrust ball bearing to ISO 104: 460 mm shaft-washer bore, 560 mm outside diameter, 80 mm stack height (18.11 x 22.047 x 3.15 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 525 kN, C0a 3000 kN and a 60 kN fatigue load limit Pu; the grease limiting speed is 390 r/min and the oil rating 560 r/min; mass about 41600 g."
      },
      {
        "q": "How is the 51192 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 92 encodes the 460 mm bore (bore code x 5). The 560 mm OD and 80 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51192 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51192?",
        "a": "At the 390 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51192?",
        "a": "The 460/560/80 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 525 kN / C0a 3000 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51192-F",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51192",
      "51192"
    ],
    "locale_variants": {}
  },
  {
    "sku": "51196",
    "brand": "NTN",
    "manufacturer_designation": "NTN 51196",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 480,
    "D_mm": 580,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 525,
    "static_load_kN": 3100,
    "fatigue_load_limit_kN": 60.5,
    "limiting_speed_rpm": 380,
    "max_rpm": 380,
    "speed_oil_rpm": 550,
    "weight_g": 43300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "In NTN Ball and Roller Bearings CAT.No.2203E, 51196 appears as a light-section 51100 thrust family bearing with a 480 mm shaft washer, a 580 mm housing diameter and 80 mm of stack height. NTN builds the number from 511 is the dimension series (light-section 51100 thrust family); 96 encodes the 480 mm bore (bore code x 5). NTN prints 525 kN axial dynamic and 3100 kN axial static for this size and a 60.5 kN fatigue load limit Pu. For a 480 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast. ",
    "applications": [
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track",
      "lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced"
    ],
    "pitfalls": [
      "For a 480 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 480 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Swapping the shaft and housing washers is an easy assembly error on the 480 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.",
      "Single-direction means exactly that: thrust on 51196 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "The Ca 525/C0a 3100 kN ratings and 60.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51196; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 51196?",
        "a": "51196 is a single-direction thrust ball bearing to ISO 104: 480 mm shaft-washer bore, 580 mm outside diameter, 80 mm stack height (18.898 x 22.835 x 3.15 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 525 kN, C0a 3100 kN and a 60.5 kN fatigue load limit Pu; the grease limiting speed is 380 r/min and the oil rating 550 r/min; mass about 43300 g."
      },
      {
        "q": "How is the 51196 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); 96 encodes the 480 mm bore (bore code x 5). The 580 mm OD and 80 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 51196 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 51196?",
        "a": "At the 380 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 51196?",
        "a": "The 480/580/80 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 525 kN / C0a 3100 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "51196-F",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 480×580×80 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊51196",
      "51196"
    ],
    "locale_variants": {}
  },
  {
    "sku": "511-500",
    "brand": "NTN",
    "manufacturer_designation": "NTN 511/500",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 500,
    "D_mm": 600,
    "B_mm": 80,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 575,
    "static_load_kN": 3400,
    "fatigue_load_limit_kN": 65.5,
    "limiting_speed_rpm": 370,
    "max_rpm": 370,
    "speed_oil_rpm": 540,
    "weight_g": 45000,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "NTN 511/500 belongs to the light-section 51100 thrust family of single-direction thrust ball bearings: 500 / 600 / 80 mm (shaft bore / OD / height). The designation is 511 is the dimension series (light-section 51100 thrust family) plus the part after the slash is the bore itself — 500 mm — used because the size falls outside the bore-code plan. NTN prints 575 kN axial dynamic and 3400 kN axial static for this size and a 65.5 kN fatigue load limit Pu. Selection starts from the load direction: if thrust ever reverses, plan a second thrust bearing (or a double-direction execution) rather than relying on the unloaded raceway. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it. ",
    "applications": [
      "heavy press and mill screwdown thrust seats",
      "crane slew-ring auxiliary thrust positions",
      "large mixer and reactor vertical shafts",
      "bulk-handler stacker/reclaimer thrust pivots"
    ],
    "failure_modes": [
      "cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers",
      "fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track",
      "early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction",
      "cage breakage after repeated shock reversal banged the ball set against the pocket bridges",
      "contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats"
    ],
    "pitfalls": [
      "For a 500 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 500 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Shock thrust above C0a 3400 kN leaves dents that later become fatigue origins — crane-hook and press applications need the static check, not just the life calculation.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "Do not reuse a thrust bearing to \"absorb\" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.",
      "The Ca 575/C0a 3400 kN ratings and 65.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 511/500; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 511/500?",
        "a": "511/500 is a single-direction thrust ball bearing to ISO 104: 500 mm shaft-washer bore, 600 mm outside diameter, 80 mm stack height (19.685 x 23.622 x 3.15 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 575 kN, C0a 3400 kN and a 65.5 kN fatigue load limit Pu; the grease limiting speed is 370 r/min and the oil rating 540 r/min; mass about 45000 g."
      },
      {
        "q": "How is the 511/500 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); the part after the slash is the bore itself — 500 mm — used because the size falls outside the bore-code plan. The 600 mm OD and 80 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 511/500 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 511/500?",
        "a": "At the 370 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 511/500?",
        "a": "The 500/600/80 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 575 kN / C0a 3400 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "511",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊511-500",
      "511-500"
    ],
    "locale_variants": {}
  },
  {
    "sku": "511-530",
    "brand": "NTN",
    "manufacturer_designation": "NTN 511/530",
    "series": "51100-series",
    "type": "thrust_ball",
    "d_mm": 530,
    "D_mm": 640,
    "B_mm": 85,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "dynamic_load_kN": 645,
    "static_load_kN": 4000,
    "fatigue_load_limit_kN": 74.5,
    "limiting_speed_rpm": 350,
    "max_rpm": 350,
    "speed_oil_rpm": 500,
    "weight_g": 55800,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 104",
    "naming_rule_text": "At 530 x 640 x 85 mm, NTN 511/530 sits in the light-section 51100 thrust family of the single-direction thrust programme. Reading the code: 511 is the dimension series (light-section 51100 thrust family), and the part after the slash is the bore itself — 530 mm — used because the size falls outside the bore-code plan. With Ca 645 kN and C0a 4000 kN, each mm of shaft bore carries about 1.22 kN of dynamic axial rating. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 511/530 cannot. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 640 mm OD already tilts the raceway and concentrates the 4000 kN static capacity on a few balls. ",
    "applications": [
      "bulk-handler stacker/reclaimer thrust pivots",
      "heavy rotary furnace and kiln thrust points",
      "vertical hydro and pump-turbine thrust supports",
      "large marine winch and windlass shafts"
    ],
    "failure_modes": [
      "ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this",
      "housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque",
      "rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only",
      "washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting",
      "edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track"
    ],
    "pitfalls": [
      "For a 530 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind \"premature\" failures.",
      "The 511 light section is the speed-friendly end of the thrust-ball plan — for the same 530 mm bore it gives up load to gain OD, height and limiting-speed headroom.",
      "Single-direction means exactly that: thrust on 511/530 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.",
      "Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 511/530 has no radial capacity at all.",
      "Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.",
      "The Ca 645/C0a 4000 kN ratings and 74.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 511/530; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make."
    ],
    "faq": [
      {
        "q": "What are the dimensions and catalogue ratings of NTN 511/530?",
        "a": "511/530 is a single-direction thrust ball bearing to ISO 104: 530 mm shaft-washer bore, 640 mm outside diameter, 85 mm stack height (20.866 x 25.197 x 3.346 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 645 kN, C0a 4000 kN and a 74.5 kN fatigue load limit Pu; the grease limiting speed is 350 r/min and the oil rating 500 r/min; mass about 55800 g."
      },
      {
        "q": "How is the 511/530 designation structured?",
        "a": "511 is the dimension series (light-section 51100 thrust family); the part after the slash is the bore itself — 530 mm — used because the size falls outside the bore-code plan. The 640 mm OD and 85 mm height follow the ISO 104 boundary plan for that series."
      },
      {
        "q": "Can 511/530 carry radial load or reversing thrust?",
        "a": "No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution."
      },
      {
        "q": "Why does NTN specify a minimum axial load for 511/530?",
        "a": "At the 350 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling."
      },
      {
        "q": "What should be checked before substituting another make for 511/530?",
        "a": "The 530/640/85 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 645 kN / C0a 4000 kN, the speed figures and the shaft/housing washer identification against the donor catalogue."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "511",
        "equiv_brand": "ISO 15",
        "level": "full",
        "note": "ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/ntn_ball_roller_2203E.pdf#page=227",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203E",
    "extracted_at": "2026-10-01",
    "last_verified": "2026-10-01",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "＊511-530",
      "511-530"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61800-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6800",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 19,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.03,
    "static_load_kN": 0.93,
    "fatigue_load_limit_kN": 0.07,
    "limiting_speed_rpm": 32000,
    "max_rpm": 32000,
    "weight_g": 5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61800 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 10 by five gives the 10 mm bore; the 19 mm outside diameter and 5 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 10 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 10 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61800 with C3 for those conditions.",
      "The 618xx thin section at 10 mm bore has only a 4.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6210.",
      "The open 61800-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 10×19×5 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 61800-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61800 units.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 19 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61800-NTN.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 5 mm-wide ring of 61800-NTN drags the lip and overheats it.",
      "The open 61800 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 10 mm bore the 61800 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 32000 r/min grease limiting speed puts 61800 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "At 2.03 kN dynamic load rating (C) and 0.93 kN static (C0), 0.07 kN fatigue load limit Cu, 61800 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 5 g, 61800 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 10×19×5 mm envelope of 61800 gives a D/d ratio of 1.90 and 4.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 2.03/0.93 kN load ratings, 0.07 kN fatigue load limit Cu NTN lists the grease limiting speed at 32000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 5 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6800 on the 10×19×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61800 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Standard catalogue stock of 61800 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61800-NTN bearing?",
        "a": "A 61800-NTN deep-groove ball bearing has a 10 mm bore, 19 mm outer diameter and 5 mm width (0.394 × 0.748 × 0.197 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 61800 compare with other series at the same 10 mm bore?",
        "a": "618 is an extra-thin section: 19×5 mm, only 4.5 mm radial section at 10 mm bore, far smaller than a 6210, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "Are 61800 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61800 uses the same ISO 15 envelope (10×19×5 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 61800?",
        "a": "NTN lists the open 61800 under the bare designation 6800; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 10 mm bore envelope."
      },
      {
        "q": "Does NTN offer 61800 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6800 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61800-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61800-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61800-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61800",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6800",
      "61800",
      "61800-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61800-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6800LLU",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 19,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.03,
    "static_load_kN": 0.93,
    "fatigue_load_limit_kN": 0.07,
    "limiting_speed_rpm": 24000,
    "max_rpm": 24000,
    "weight_g": 5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61800-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 10 by five gives the 10 mm bore; the 19 mm outside diameter and 5 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 10 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6800LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "At 10 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61800 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 618xx thin section at 10 mm bore has only a 4.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6210.",
      "Contact seals add drag and heat: 61800-2RS-NTN runs slower and cooler-limited than the open 61800; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 61800-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Vibration during standstill brinells the raceways of a 10 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "The housing bore for the 19 mm OD should be round within IT7; an oval bore pinches the outer ring of 61800-2RS-NTN and shows up later as two-point loaded raceway wear.",
      "NTN catalogues the contact-sealed version as 6800LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 10 mm bore the 61800 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61800 at 24000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 2.03 kN dynamic load rating (C) and 0.93 kN static (C0), 0.07 kN fatigue load limit Cu, 61800 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 5 g, 61800 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 10×19×5 mm envelope of 61800 gives a D/d ratio of 1.90 and 4.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 2.03/0.93 kN load ratings, 0.07 kN fatigue load limit Cu NTN lists the grease limiting speed at 24000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 5 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6800LLU on the 10×19×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61800 in a rated drive.",
      "Standard catalogue stock of 61800 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61800-2RS-NTN bearing?",
        "a": "A 61800-2RS-NTN deep-groove ball bearing has a 10 mm bore, 19 mm outer diameter and 5 mm width (0.394 × 0.748 × 0.197 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 61800 bore code work?",
        "a": "The last two digits of 61800 are bore code 10, giving 10 × 5 = 10 mm bore. The 19 mm outside diameter and 5 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the 2RS suffix on 61800-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "What is the NTN suffix for a sealed 61800?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6800LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 10×19×5 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61800 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6800LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61800-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61800-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61800-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61800",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61800-llu",
      "6800llu",
      "61800-2RS",
      "61800-2rs",
      "6800LLU",
      "61800-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61800-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6800LLB",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 19,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.03,
    "static_load_kN": 0.93,
    "fatigue_load_limit_kN": 0.07,
    "limiting_speed_rpm": 32000,
    "max_rpm": 32000,
    "weight_g": 5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61800-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 10 by five gives the 10 mm bore; the 19 mm outside diameter and 5 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 10 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6800LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Interference on a 10 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61800 with C3 clearance and re-check the residual value after mounting.",
      "The 618xx thin section at 10 mm bore has only a 4.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6210.",
      "RSR low-friction seals on 61800-RSR-NTN run faster than contact-seal 61800-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61800-2RS instead.",
      "The non-contact lip of 61800-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 10 mm bore position before relying on it as sealed-for-life.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 5 mm-wide ring of 61800-RSR-NTN drags the lip and overheats it.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues this low-friction non-contact seal as 6800LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 10 mm bore the 61800 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 32000 r/min grease limiting speed puts 61800 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "At 2.03 kN dynamic load rating (C) and 0.93 kN static (C0), 0.07 kN fatigue load limit Cu, 61800 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 5 g, 61800 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 10×19×5 mm envelope of 61800 gives a D/d ratio of 1.90 and 4.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 2.03/0.93 kN load ratings, 0.07 kN fatigue load limit Cu NTN lists the grease limiting speed at 32000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 5 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6800LLB on the 10×19×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61800 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61800 is listed.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61800-RSR-NTN bearing?",
        "a": "A 61800-RSR-NTN deep-groove ball bearing has a 10 mm bore, 19 mm outer diameter and 5 mm width (0.394 × 0.748 × 0.197 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 61800 compare with other series at the same 10 mm bore?",
        "a": "618 is an extra-thin section: 19×5 mm, only 4.5 mm radial section at 10 mm bore, far smaller than a 6210, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "Are 61800 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61800 uses the same ISO 15 envelope (10×19×5 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61800?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6800LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 10×19×5 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61800 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6800LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61800-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61800-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61800-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61800",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61800-llb",
      "6800llb",
      "61800-RSR",
      "61800-rsr",
      "6800LLB",
      "61800-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61800-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6800ZZ",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 19,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.03,
    "static_load_kN": 0.93,
    "fatigue_load_limit_kN": 0.07,
    "limiting_speed_rpm": 32000,
    "max_rpm": 32000,
    "weight_g": 5,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61800 carries bore code 10 = 10 mm. Outside diameter 19 mm and width 5 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 10 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6800ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Interference on a 10 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61800 with C3 clearance and re-check the residual value after mounting.",
      "The 618xx thin section at 10 mm bore has only a 4.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6210.",
      "Do not wash 61800-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 61800-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Vibration during standstill brinells the raceways of a 10 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Shaft and housing fillets must clear the bearing chamfer so the 5 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues the shielded version as 6800ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 10 mm bore the 61800 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 32000 r/min grease limiting speed puts 61800 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "At 2.03 kN dynamic load rating (C) and 0.93 kN static (C0), 0.07 kN fatigue load limit Cu, 61800 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 5 g, 61800 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 10×19×5 mm envelope of 61800 gives a D/d ratio of 1.90 and 4.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 2.03/0.93 kN load ratings, 0.07 kN fatigue load limit Cu NTN lists the grease limiting speed at 32000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 5 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6800ZZ on the 10×19×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61800 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61800-ZZ-NTN bearing?",
        "a": "A 61800-ZZ-NTN deep-groove ball bearing has a 10 mm bore, 19 mm outer diameter and 5 mm width (0.394 × 0.748 × 0.197 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How should 61800-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 10 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 61800-ZZ-NTN need?",
        "a": "61800-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "What is the NTN suffix for a sealed 61800?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6800ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 10×19×5 mm ISO 15 envelope."
      },
      {
        "q": "Is 6800ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61800-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61800-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61800-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61800-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61800",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×19×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61800-zz",
      "6800zz",
      "61800-ZZ",
      "6800ZZ",
      "61800-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61900-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6900",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 22,
    "B_mm": 6,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.99,
    "static_load_kN": 1.27,
    "fatigue_load_limit_kN": 0.1,
    "limiting_speed_rpm": 30000,
    "max_rpm": 30000,
    "weight_g": 9,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61900 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 10 by five gives the 10 mm bore; the 22 mm outside diameter and 6 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 10 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Interference on a 10 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61900 with C3 clearance and re-check the residual value after mounting.",
      "The 619xx thin section (6.0 mm section height at 10 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "The open 61900-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 10×22×6 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 61900-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Vibration during standstill brinells the raceways of a 10 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "The open 61900 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 10 mm bore the 61900 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 30000 r/min grease limiting speed puts 61900 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "At 2.99 kN dynamic load rating (C) and 1.27 kN static (C0), 0.1 kN fatigue load limit Cu, 61900 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 9 g, 61900 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 10×22×6 mm envelope of 61900 gives a D/d ratio of 2.20 and 6.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 2.99/1.27 kN load ratings, 0.1 kN fatigue load limit Cu NTN lists the grease limiting speed at 30000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 9 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6900 on the 10×22×6 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61900 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61900-NTN bearing?",
        "a": "A 61900-NTN deep-groove ball bearing has a 10 mm bore, 22 mm outer diameter and 6 mm width (0.394 × 0.866 × 0.236 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How should 61900-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 10 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 61900-NTN need?",
        "a": "The open 61900-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "What is the NTN order number for an open 61900?",
        "a": "NTN lists the open 61900 under the bare designation 6900; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 10 mm bore envelope."
      },
      {
        "q": "Does NTN offer 61900 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6900 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61900-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61900-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61900-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61900",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6900",
      "61900",
      "61900-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61900-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6900LLU",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 22,
    "B_mm": 6,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.99,
    "static_load_kN": 1.27,
    "fatigue_load_limit_kN": 0.1,
    "limiting_speed_rpm": 21000,
    "max_rpm": 21000,
    "weight_g": 9,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61900 carries bore code 10 = 10 mm. Outside diameter 22 mm and width 6 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 10 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6900LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Interference on a 10 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61900 with C3 clearance and re-check the residual value after mounting.",
      "The 619xx thin section at 10 mm bore (6.0 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "Contact seals add drag and heat: 61900-2RS-NTN runs slower and cooler-limited than the open 61900; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 61900-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Shaft and housing fillets must clear the bearing chamfer so the 6 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Vibration during standstill brinells the raceways of a 10 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues the contact-sealed version as 6900LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 10 mm bore the 61900 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61900 at 21000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 2.99 kN dynamic load rating (C) and 1.27 kN static (C0), 0.1 kN fatigue load limit Cu, 61900 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 9 g, 61900 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 10×22×6 mm envelope of 61900 gives a D/d ratio of 2.20 and 6.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 2.99/1.27 kN load ratings, 0.1 kN fatigue load limit Cu NTN lists the grease limiting speed at 21000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 9 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6900LLU on the 10×22×6 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61900 in a rated drive.",
      "Standard catalogue stock of 61900 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61900-2RS-NTN bearing?",
        "a": "A 61900-2RS-NTN deep-groove ball bearing has a 10 mm bore, 22 mm outer diameter and 6 mm width (0.394 × 0.866 × 0.236 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "Are 61900 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61900 uses the same ISO 15 envelope (10×22×6 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 61900-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61900-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61900 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 61900?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6900LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 10×22×6 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6900LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61900-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61900-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61900-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61900",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61900-llu",
      "6900llu",
      "61900-2RS",
      "61900-2rs",
      "6900LLU",
      "61900-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61900-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6900LLB",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 22,
    "B_mm": 6,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.99,
    "static_load_kN": 1.27,
    "fatigue_load_limit_kN": 0.1,
    "limiting_speed_rpm": 25000,
    "max_rpm": 25000,
    "weight_g": 9,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61900 carries bore code 10 = 10 mm. Outside diameter 22 mm and width 6 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 10 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6900LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 10 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61900 with C3 for those conditions.",
      "The 619xx thin section (6.0 mm section height at 10 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "RSR low-friction seals on 61900-RSR-NTN run faster than contact-seal 61900-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61900-2RS instead.",
      "The non-contact lip of 61900-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 10 mm bore position before relying on it as sealed-for-life.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61900-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues this low-friction non-contact seal as 6900LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 10 mm bore the 61900 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 25000 r/min grease limiting speed puts 61900 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "At 2.99 kN dynamic load rating (C) and 1.27 kN static (C0), 0.1 kN fatigue load limit Cu, 61900 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 9 g, 61900 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 10×22×6 mm envelope of 61900 gives a D/d ratio of 2.20 and 6.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 2.99/1.27 kN load ratings, 0.1 kN fatigue load limit Cu NTN lists the grease limiting speed at 25000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 9 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6900LLB on the 10×22×6 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61900 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61900 is listed.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61900-RSR-NTN bearing?",
        "a": "A 61900-RSR-NTN deep-groove ball bearing has a 10 mm bore, 22 mm outer diameter and 6 mm width (0.394 × 0.866 × 0.236 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 61900 compare with other series at the same 10 mm bore?",
        "a": "619 is a thin section one step above 618: 22×6 mm with a 6.0 mm radial section at 10 mm bore; a 6210 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "Are 61900 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61900 uses the same ISO 15 envelope (10×22×6 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61900?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6900LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 10×22×6 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6900LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61900-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61900-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61900-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61900",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61900-llb",
      "6900llb",
      "61900-RSR",
      "61900-rsr",
      "6900LLB",
      "61900-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61900-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6900ZZ",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 22,
    "B_mm": 6,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.99,
    "static_load_kN": 1.27,
    "fatigue_load_limit_kN": 0.1,
    "limiting_speed_rpm": 25000,
    "max_rpm": 25000,
    "weight_g": 9,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61900-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 10 by five gives the 10 mm bore; the 22 mm outside diameter and 6 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 10 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6900ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 10 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61900 with C3 for those conditions.",
      "The 619xx thin section at 10 mm bore (6.0 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "ZZ shields are non-contact: 61900-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61900-2RS for that.",
      "Do not wash 61900-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "A 10 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Never mix components between two 61900-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the shielded version as 6900ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 10 mm bore the 61900 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 25000 r/min grease limiting speed puts 61900 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "At 2.99 kN dynamic load rating (C) and 1.27 kN static (C0), 0.1 kN fatigue load limit Cu, 61900 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 9 g, 61900 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 10×22×6 mm envelope of 61900 gives a D/d ratio of 2.20 and 6.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 2.99/1.27 kN load ratings, 0.1 kN fatigue load limit Cu NTN lists the grease limiting speed at 25000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 9 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6900ZZ on the 10×22×6 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61900 in a rated drive.",
      "Order the C3 internal-clearance version (61900 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Standard catalogue stock of 61900 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61900-ZZ-NTN bearing?",
        "a": "A 61900-ZZ-NTN deep-groove ball bearing has a 10 mm bore, 22 mm outer diameter and 6 mm width (0.394 × 0.866 × 0.236 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What internal clearance does 61900-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61900-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61900 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61900-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 10 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 61900?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6900ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 10×22×6 mm ISO 15 envelope."
      },
      {
        "q": "Is 6900ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61900-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61900-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61900-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61900-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61900",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×22×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61900-zz",
      "6900zz",
      "61900-ZZ",
      "6900ZZ",
      "61900-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6200-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6200",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 30,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.65,
    "static_load_kN": 2.39,
    "fatigue_load_limit_kN": 0.18,
    "limiting_speed_rpm": 25000,
    "max_rpm": 25000,
    "weight_g": 32,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6200 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 10 by five gives the 10 mm bore; the 30 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 10 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 10 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6200 with C3 for those conditions.",
      "The 62xx light series is the default general-purpose section at 10 mm bore; before upgrading to a 6310 for extra capacity, confirm the housing accepts a 30 mm OD and 9 mm width — it is not a drop-in swap.",
      "The open 6200-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 10×30×9 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6200-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Never mix components between two 6200-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6200-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "The open 6200 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 10 mm bore the 6200 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 25000 r/min grease limiting speed puts 6200 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "NTN rates 6200 at 5.65 kN dynamic (C) and 2.39 kN static (C0), 0.18 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 32 g, 6200 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 10×30×9 mm envelope of 6200 gives a D/d ratio of 3.00 and 10.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 5.65/2.39 kN load ratings, 0.18 kN fatigue load limit Cu NTN lists the grease limiting speed at 25000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 32 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6200 on the 10×30×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6200 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6200 is listed.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6200-NTN bearing?",
        "a": "A 6200-NTN deep-groove ball bearing has a 10 mm bore, 30 mm outer diameter and 9 mm width (0.394 × 1.181 × 0.354 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How should 6200-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 10 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6200-NTN need?",
        "a": "The open 6200-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "What is the NTN order number for an open 6200?",
        "a": "NTN lists the open 6200 under the bare designation 6200; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 10 mm bore envelope."
      },
      {
        "q": "Is 6200 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6200-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6200-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6200-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6200",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6200",
      "6200-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6200-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6200LLU",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 30,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.65,
    "static_load_kN": 2.39,
    "fatigue_load_limit_kN": 0.18,
    "limiting_speed_rpm": 18000,
    "max_rpm": 18000,
    "weight_g": 32,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6200 carries bore code 10 = 10 mm. Outside diameter 30 mm and width 9 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 10 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6200LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Interference on a 10 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6200 with C3 clearance and re-check the residual value after mounting.",
      "At 10 mm bore the 62xx light series is the workhorse section; its 30×9 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "Heat is the enemy of the sealed 6200-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 6200-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "A 10 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Never mix components between two 6200-2RS-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the contact-sealed version as 6200LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 10 mm bore the 6200 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6200 at 18000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6200 at 5.65 kN dynamic (C) and 2.39 kN static (C0), 0.18 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 32 g, 6200 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 10×30×9 mm envelope of 6200 gives a D/d ratio of 3.00 and 10.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 5.65/2.39 kN load ratings, 0.18 kN fatigue load limit Cu NTN lists the grease limiting speed at 18000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 32 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6200LLU on the 10×30×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6200 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6200 is listed.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6200-2RS-NTN bearing?",
        "a": "A 6200-2RS-NTN deep-groove ball bearing has a 10 mm bore, 30 mm outer diameter and 9 mm width (0.394 × 1.181 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What lubrication does 6200-2RS-NTN need?",
        "a": "6200-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6200 with a housing grease fitting instead."
      },
      {
        "q": "How does the 6200 bore code work?",
        "a": "The last two digits of 6200 are bore code 10, giving 10 × 5 = 10 mm bore. The 30 mm outside diameter and 9 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6200?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6200LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 10×30×9 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6200LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6200-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6200-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6200-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6200",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6200-llu",
      "6200llu",
      "6200-2RS",
      "6200-2rs",
      "6200LLU",
      "6200-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6200-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6200LLB",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 30,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.65,
    "static_load_kN": 2.39,
    "fatigue_load_limit_kN": 0.18,
    "limiting_speed_rpm": 21000,
    "max_rpm": 21000,
    "weight_g": 32,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6200 carries bore code 10 = 10 mm. Outside diameter 30 mm and width 9 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 10 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6200LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 10 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6200 with C3 for those conditions.",
      "The 62xx light series is the default general-purpose section at 10 mm bore; before upgrading to a 6310 for extra capacity, confirm the housing accepts a 30 mm OD and 9 mm width — it is not a drop-in swap.",
      "RSR low-friction seals on 6200-RSR-NTN run faster than contact-seal 6200-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6200-2RS instead.",
      "The low-drag lip of 6200-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6200-RSR-NTN-C3. No clearance suffix means normal CN clearance.",
      "NTN catalogues this low-friction non-contact seal as 6200LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 10 mm bore the 6200 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6200 at 21000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6200 at 5.65 kN dynamic (C) and 2.39 kN static (C0), 0.18 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 32 g, 6200 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 10×30×9 mm envelope of 6200 gives a D/d ratio of 3.00 and 10.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 5.65/2.39 kN load ratings, 0.18 kN fatigue load limit Cu NTN lists the grease limiting speed at 21000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 32 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6200LLB on the 10×30×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6200 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6200-RSR-NTN bearing?",
        "a": "A 6200-RSR-NTN deep-groove ball bearing has a 10 mm bore, 30 mm outer diameter and 9 mm width (0.394 × 1.181 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What lubrication does 6200-RSR-NTN need?",
        "a": "6200-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6200 with a housing grease fitting instead."
      },
      {
        "q": "How does the 6200 bore code work?",
        "a": "The last two digits of 6200 are bore code 10, giving 10 × 5 = 10 mm bore. The 30 mm outside diameter and 9 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6200?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6200LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 10×30×9 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6200LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6200-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6200-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6200-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6200",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6200-llb",
      "6200llb",
      "6200-RSR",
      "6200-rsr",
      "6200LLB",
      "6200-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6200-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6200ZZ",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 30,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.65,
    "static_load_kN": 2.39,
    "fatigue_load_limit_kN": 0.18,
    "limiting_speed_rpm": 21000,
    "max_rpm": 21000,
    "weight_g": 32,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6200 carries bore code 10 = 10 mm. Outside diameter 30 mm and width 9 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 10 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6200ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Interference on a 10 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6200 with C3 clearance and re-check the residual value after mounting.",
      "At 10 mm bore the 62xx light series is the workhorse section; its 30×9 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "ZZ shields are non-contact: 6200-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6200-2RS for that.",
      "Do not wash 6200-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "A 10 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "The housing bore for the 30 mm OD should be round within IT7; an oval bore pinches the outer ring of 6200-ZZ-NTN and shows up later as two-point loaded raceway wear.",
      "NTN catalogues the shielded version as 6200ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 10 mm bore the 6200 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6200 at 21000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6200 at 5.65 kN dynamic (C) and 2.39 kN static (C0), 0.18 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 32 g, 6200 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 10×30×9 mm envelope of 6200 gives a D/d ratio of 3.00 and 10.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 5.65/2.39 kN load ratings, 0.18 kN fatigue load limit Cu NTN lists the grease limiting speed at 21000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 32 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6200ZZ on the 10×30×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6200 in a rated drive.",
      "Standard catalogue stock of 6200 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6200 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6200-ZZ-NTN bearing?",
        "a": "A 6200-ZZ-NTN deep-groove ball bearing has a 10 mm bore, 30 mm outer diameter and 9 mm width (0.394 × 1.181 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "Are 6200 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6200 uses the same ISO 15 envelope (10×30×9 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 6200-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6200-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6200 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 6200?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6200ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 10×30×9 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6200 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6200ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6200-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6200-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6200-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6200-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6200",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×30×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6200-zz",
      "6200zz",
      "6200-ZZ",
      "6200ZZ",
      "6200-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6300-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6300",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 35,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 9.1,
    "static_load_kN": 3.5,
    "fatigue_load_limit_kN": 0.27,
    "limiting_speed_rpm": 23000,
    "max_rpm": 23000,
    "weight_g": 53,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6300 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 10 by five gives the 10 mm bore; the 35 mm outside diameter and 11 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 10 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "conveyor drives",
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 10 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6300 with C3 for those conditions.",
      "The 63xx medium section at 10 mm bore gains dynamic rating through larger rolling elements on a 35 mm OD; the penalty is mass and a lower limiting speed than the 6210 — do not specify it for speed-critical shafts.",
      "The open 6300-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 10×35×11 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6300-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "The housing bore for the 35 mm OD should be round within IT7; an oval bore pinches the outer ring of 6300-NTN and shows up later as two-point loaded raceway wear.",
      "A 10 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "The open 6300 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 10 mm bore the 6300 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6300 at 23000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 6300 at 9.1 kN dynamic (C) and 3.5 kN static (C0), 0.27 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 53 g, 6300 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 10×35×11 mm envelope of 6300 gives a D/d ratio of 3.50 and 12.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 9.1/3.5 kN load ratings, 0.27 kN fatigue load limit Cu NTN lists the grease limiting speed at 23000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 53 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6300 on the 10×35×11 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6300 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6300-NTN bearing?",
        "a": "A 6300-NTN deep-groove ball bearing has a 10 mm bore, 35 mm outer diameter and 11 mm width (0.394 × 1.378 × 0.433 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6300 bore code work?",
        "a": "The last two digits of 6300 are bore code 10, giving 10 × 5 = 10 mm bore. The 35 mm outside diameter and 11 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does no suffix on 6300 mean?",
        "a": "A bare 6300 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "What is the NTN order number for an open 6300?",
        "a": "NTN lists the open 6300 under the bare designation 6300; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 10 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6300?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6300-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6300-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6300-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6300",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6300",
      "6300-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6300-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6300LLU",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 35,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 9.1,
    "static_load_kN": 3.5,
    "fatigue_load_limit_kN": 0.27,
    "limiting_speed_rpm": 16000,
    "max_rpm": 16000,
    "weight_g": 53,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6300-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 10 by five gives the 10 mm bore; the 35 mm outside diameter and 11 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 10 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6300LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "At 10 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6300 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 63xx medium series gains rating at 10 mm bore through a 35 mm OD and 11 mm width; the heavier rolling elements also trade away some speed versus a 6210.",
      "Heat is the enemy of the sealed 6300-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 6300-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 11 mm-wide ring of 6300-2RS-NTN drags the lip and overheats it.",
      "Measure the shaft, do not trust the drawing: a 10 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6300-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6300LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 10 mm bore the 6300 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6300 at 16000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6300 at 9.1 kN dynamic (C) and 3.5 kN static (C0), 0.27 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 53 g, 6300 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 10×35×11 mm envelope of 6300 gives a D/d ratio of 3.50 and 12.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 9.1/3.5 kN load ratings, 0.27 kN fatigue load limit Cu NTN lists the grease limiting speed at 16000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 53 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6300LLU on the 10×35×11 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6300 in a rated drive.",
      "Order the C3 internal-clearance version (6300 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6300-2RS-NTN bearing?",
        "a": "A 6300-2RS-NTN deep-groove ball bearing has a 10 mm bore, 35 mm outer diameter and 11 mm width (0.394 × 1.378 × 0.433 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 6300 bore code work?",
        "a": "The last two digits of 6300 are bore code 10, giving 10 × 5 = 10 mm bore. The 35 mm outside diameter and 11 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the 2RS suffix on 6300-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "What is the NTN suffix for a sealed 6300?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6300LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 10×35×11 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6300 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6300LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6300-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6300-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6300-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6300",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6300-llu",
      "6300llu",
      "6300-2RS",
      "6300-2rs",
      "6300LLU",
      "6300-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6300-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6300LLB",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 35,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 9.1,
    "static_load_kN": 3.5,
    "fatigue_load_limit_kN": 0.27,
    "limiting_speed_rpm": 20000,
    "max_rpm": 20000,
    "weight_g": 53,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6300 carries bore code 10 = 10 mm. Outside diameter 35 mm and width 11 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 10 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6300LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "At 10 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6300 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 63xx medium section at 10 mm bore gains dynamic rating through larger rolling elements on a 35 mm OD; the penalty is mass and a lower limiting speed than the 6210 — do not specify it for speed-critical shafts.",
      "The low-drag lip of 6300-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 6300-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 10 mm bore position before relying on it as sealed-for-life.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 11 mm-wide ring of 6300-RSR-NTN drags the lip and overheats it.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 35 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6300-RSR-NTN.",
      "NTN catalogues this low-friction non-contact seal as 6300LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 10 mm bore the 6300 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6300 at 20000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6300 at 9.1 kN dynamic (C) and 3.5 kN static (C0), 0.27 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 53 g, 6300 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 10×35×11 mm envelope of 6300 gives a D/d ratio of 3.50 and 12.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 9.1/3.5 kN load ratings, 0.27 kN fatigue load limit Cu NTN lists the grease limiting speed at 20000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 53 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6300LLB on the 10×35×11 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6300 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6300 is listed.",
      "Order the C3 internal-clearance version (6300 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6300-RSR-NTN bearing?",
        "a": "A 6300-RSR-NTN deep-groove ball bearing has a 10 mm bore, 35 mm outer diameter and 11 mm width (0.394 × 1.378 × 0.433 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How should 6300-RSR-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 10 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6300-RSR-NTN need?",
        "a": "6300-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6300 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 6300?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6300LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 10×35×11 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6300LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6300-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6300-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6300-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6300",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6300-llb",
      "6300llb",
      "6300-RSR",
      "6300-rsr",
      "6300LLB",
      "6300-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6300-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6300ZZ",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 10,
    "D_mm": 35,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 9.1,
    "static_load_kN": 3.5,
    "fatigue_load_limit_kN": 0.27,
    "limiting_speed_rpm": 20000,
    "max_rpm": 20000,
    "weight_g": 53,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6300 carries bore code 10 = 10 mm. Outside diameter 35 mm and width 11 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 10 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6300ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "conveyor drives",
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Interference on a 10 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6300 with C3 clearance and re-check the residual value after mounting.",
      "The 63xx medium series gains rating at 10 mm bore through a 35 mm OD and 11 mm width; the heavier rolling elements also trade away some speed versus a 6210.",
      "ZZ shields are non-contact: 6300-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6300-2RS for that.",
      "Do not wash 6300-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6300-ZZ-NTN-C3. No clearance suffix means normal CN clearance.",
      "Never mix components between two 6300-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the shielded version as 6300ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 10 mm bore the 6300 sits in NTN's miniature range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6300 at 20000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6300 at 9.1 kN dynamic (C) and 3.5 kN static (C0), 0.27 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 53 g, 6300 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 10×35×11 mm envelope of 6300 gives a D/d ratio of 3.50 and 12.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 9.1/3.5 kN load ratings, 0.27 kN fatigue load limit Cu NTN lists the grease limiting speed at 20000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 53 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6300ZZ on the 10×35×11 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6300 in a rated drive.",
      "Order the C3 internal-clearance version (6300 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6300-ZZ-NTN bearing?",
        "a": "A 6300-ZZ-NTN deep-groove ball bearing has a 10 mm bore, 35 mm outer diameter and 11 mm width (0.394 × 1.378 × 0.433 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "Are 6300 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6300 uses the same ISO 15 envelope (10×35×11 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 6300-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6300-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6300 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 6300?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6300ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 10×35×11 mm ISO 15 envelope."
      },
      {
        "q": "Is 6300ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6300-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6300-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6300-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6300-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6300",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 10×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6300-zz",
      "6300zz",
      "6300-ZZ",
      "6300ZZ",
      "6300-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61801-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6801",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 21,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.12,
    "static_load_kN": 1.04,
    "fatigue_load_limit_kN": 0.08,
    "limiting_speed_rpm": 29000,
    "max_rpm": 29000,
    "weight_g": 6,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61801 carries bore code 12 = 12 mm. Outside diameter 21 mm and width 5 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Interference on a 12 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61801 with C3 clearance and re-check the residual value after mounting.",
      "The 618xx thin section at 12 mm bore has only a 4.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6212.",
      "The open 61801-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 12×21×5 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 61801-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Measure the shaft, do not trust the drawing: a 12 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61801-NTN.",
      "Never mix components between two 61801-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "The open 61801 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 12 mm bore the 61801 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 29000 r/min grease limiting speed puts 61801 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "At 2.12 kN dynamic load rating (C) and 1.04 kN static (C0), 0.08 kN fatigue load limit Cu, 61801 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 6 g, 61801 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×21×5 mm envelope of 61801 gives a D/d ratio of 1.75 and 4.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 2.12/1.04 kN load ratings, 0.08 kN fatigue load limit Cu NTN lists the grease limiting speed at 29000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 6 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6801 on the 12×21×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61801 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61801 is listed.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61801-NTN bearing?",
        "a": "A 61801-NTN deep-groove ball bearing has a 12 mm bore, 21 mm outer diameter and 5 mm width (0.472 × 0.827 × 0.197 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 61801 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61801 uses the same ISO 15 envelope (12×21×5 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 61801-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61801-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61801 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 61801?",
        "a": "NTN lists the open 61801 under the bare designation 6801; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 12 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6801?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61801-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61801-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61801-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6801",
      "61801",
      "61801-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61801-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6801LLU",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 21,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.12,
    "static_load_kN": 1.04,
    "fatigue_load_limit_kN": 0.08,
    "limiting_speed_rpm": 20000,
    "max_rpm": 20000,
    "weight_g": 6,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61801 carries bore code 12 = 12 mm. Outside diameter 21 mm and width 5 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6801LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 12 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61801 with C3 for those conditions.",
      "Only 4.5 mm of radial section separates bore and OD on the 618xx series at 12 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6212.",
      "Contact seals add drag and heat: 61801-2RS-NTN runs slower and cooler-limited than the open 61801; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 61801-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61801-2RS-NTN-C3. No clearance suffix means normal CN clearance.",
      "Shaft and housing fillets must clear the bearing chamfer so the 5 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues the contact-sealed version as 6801LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 12 mm bore the 61801 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61801 at 20000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 2.12 kN dynamic load rating (C) and 1.04 kN static (C0), 0.08 kN fatigue load limit Cu, 61801 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 6 g, 61801 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×21×5 mm envelope of 61801 gives a D/d ratio of 1.75 and 4.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 2.12/1.04 kN load ratings, 0.08 kN fatigue load limit Cu NTN lists the grease limiting speed at 20000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 6 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6801LLU on the 12×21×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61801 in a rated drive.",
      "Order the C3 internal-clearance version (61801 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61801 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61801-2RS-NTN bearing?",
        "a": "A 61801-2RS-NTN deep-groove ball bearing has a 12 mm bore, 21 mm outer diameter and 5 mm width (0.472 × 0.827 × 0.197 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What does the 2RS suffix on 61801-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "How does the 61800 compare with other series at the same 12 mm bore?",
        "a": "618 is an extra-thin section: 21×5 mm, only 4.5 mm radial section at 12 mm bore, far smaller than a 6212, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "What is the NTN suffix for a sealed 61801?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6801LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 12×21×5 mm ISO 15 envelope."
      },
      {
        "q": "Is 6801LLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61801-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61801-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61801-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61801-llu",
      "6801llu",
      "61801-2RS",
      "61801-2rs",
      "6801LLU",
      "61801-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61801-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6801LLB",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 21,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.12,
    "static_load_kN": 1.04,
    "fatigue_load_limit_kN": 0.08,
    "limiting_speed_rpm": 29000,
    "max_rpm": 29000,
    "weight_g": 6,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61801 carries bore code 12 = 12 mm. Outside diameter 21 mm and width 5 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6801LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At 12 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61801 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 618xx thin section at 12 mm bore has only a 4.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6212.",
      "RSR low-friction seals on 61801-RSR-NTN run faster than contact-seal 61801-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61801-2RS instead.",
      "The non-contact lip of 61801-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 12 mm bore position before relying on it as sealed-for-life.",
      "A 12 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Shaft and housing fillets must clear the bearing chamfer so the 5 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues this low-friction non-contact seal as 6801LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 12 mm bore the 61801 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 29000 r/min grease limiting speed puts 61801 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "At 2.12 kN dynamic load rating (C) and 1.04 kN static (C0), 0.08 kN fatigue load limit Cu, 61801 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 6 g, 61801 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×21×5 mm envelope of 61801 gives a D/d ratio of 1.75 and 4.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 2.12/1.04 kN load ratings, 0.08 kN fatigue load limit Cu NTN lists the grease limiting speed at 29000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 6 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6801LLB on the 12×21×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61801 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61801 is listed.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61801-RSR-NTN bearing?",
        "a": "A 61801-RSR-NTN deep-groove ball bearing has a 12 mm bore, 21 mm outer diameter and 5 mm width (0.472 × 0.827 × 0.197 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 61801 bore code work?",
        "a": "The last two digits of 61801 are bore code 12, giving 12 × 5 = 12 mm bore. The 21 mm outside diameter and 5 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the RSR suffix on 61801-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "What is the NTN suffix for a sealed 61801?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6801LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 12×21×5 mm ISO 15 envelope."
      },
      {
        "q": "Is 6801LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61801-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61801-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61801-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61801-llb",
      "6801llb",
      "61801-RSR",
      "61801-rsr",
      "6801LLB",
      "61801-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61801-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6801ZZ",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 21,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.12,
    "static_load_kN": 1.04,
    "fatigue_load_limit_kN": 0.08,
    "limiting_speed_rpm": 29000,
    "max_rpm": 29000,
    "weight_g": 6,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61801 carries bore code 12 = 12 mm. Outside diameter 21 mm and width 5 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6801ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 12 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61801 with C3 for those conditions.",
      "Only 4.5 mm of radial section separates bore and OD on the 618xx series at 12 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6212.",
      "Do not wash 61801-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 61801-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Never mix components between two 61801-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Measure the shaft, do not trust the drawing: a 12 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61801-ZZ-NTN.",
      "NTN catalogues the shielded version as 6801ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 12 mm bore the 61801 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 29000 r/min grease limiting speed puts 61801 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "At 2.12 kN dynamic load rating (C) and 1.04 kN static (C0), 0.08 kN fatigue load limit Cu, 61801 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 6 g, 61801 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×21×5 mm envelope of 61801 gives a D/d ratio of 1.75 and 4.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 2.12/1.04 kN load ratings, 0.08 kN fatigue load limit Cu NTN lists the grease limiting speed at 29000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 6 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6801ZZ on the 12×21×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61801 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61801 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61801-ZZ-NTN bearing?",
        "a": "A 61801-ZZ-NTN deep-groove ball bearing has a 12 mm bore, 21 mm outer diameter and 5 mm width (0.472 × 0.827 × 0.197 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 61801 bore code work?",
        "a": "The last two digits of 61801 are bore code 12, giving 12 × 5 = 12 mm bore. The 21 mm outside diameter and 5 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the ZZ suffix on 61801-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "What is the NTN suffix for a sealed 61801?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6801ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 12×21×5 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61801 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6801ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61801-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61801-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61801-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61801-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×21×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61801-zz",
      "6801zz",
      "61801-ZZ",
      "6801ZZ",
      "61801-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61901-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6901",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 24,
    "B_mm": 6,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 3.2,
    "static_load_kN": 1.46,
    "fatigue_load_limit_kN": 0.12,
    "limiting_speed_rpm": 27000,
    "max_rpm": 27000,
    "weight_g": 11,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61901 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 12 by five gives the 12 mm bore; the 24 mm outside diameter and 6 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 12 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "At 12 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61901 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 619xx thin section (6.0 mm section height at 12 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "Storage matters for open bearings: 61901-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 61900-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61901 units.",
      "Shaft and housing fillets must clear the bearing chamfer so the 6 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61900-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "The open 61901 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 12 mm bore the 61901 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 27000 r/min grease limiting speed puts 61901 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "At 3.2 kN dynamic load rating (C) and 1.46 kN static (C0), 0.12 kN fatigue load limit Cu, 61901 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 11 g, 61901 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×24×6 mm envelope of 61901 gives a D/d ratio of 2.00 and 6.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 3.2/1.46 kN load ratings, 0.12 kN fatigue load limit Cu NTN lists the grease limiting speed at 27000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 11 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6901 on the 12×24×6 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61901 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61901-NTN bearing?",
        "a": "A 61901-NTN deep-groove ball bearing has a 12 mm bore, 24 mm outer diameter and 6 mm width (0.472 × 0.945 × 0.236 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 61900 compare with other series at the same 12 mm bore?",
        "a": "619 is a thin section one step above 618: 24×6 mm with a 6.0 mm radial section at 12 mm bore; a 6212 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "Are 61901 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61901 uses the same ISO 15 envelope (12×24×6 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 61901?",
        "a": "NTN lists the open 61901 under the bare designation 6901; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 12 mm bore envelope."
      },
      {
        "q": "Does NTN offer 61901 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6901 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61901-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61901-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61901-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61901",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6901",
      "61901",
      "61901-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61901-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6901LLU",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 24,
    "B_mm": 6,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 3.2,
    "static_load_kN": 1.46,
    "fatigue_load_limit_kN": 0.12,
    "limiting_speed_rpm": 19000,
    "max_rpm": 19000,
    "weight_g": 11,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61901-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 12 by five gives the 12 mm bore; the 24 mm outside diameter and 6 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 12 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6901LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At 12 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61901 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 619xx thin section at 12 mm bore (6.0 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "Contact seals add drag and heat: 61901-2RS-NTN runs slower and cooler-limited than the open 61901; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 61901-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues the contact-sealed version as 6901LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 12 mm bore the 61901 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61901 at 19000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 3.2 kN dynamic load rating (C) and 1.46 kN static (C0), 0.12 kN fatigue load limit Cu, 61901 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 11 g, 61901 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×24×6 mm envelope of 61901 gives a D/d ratio of 2.00 and 6.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 3.2/1.46 kN load ratings, 0.12 kN fatigue load limit Cu NTN lists the grease limiting speed at 19000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 11 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6901LLU on the 12×24×6 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61901 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61901-2RS-NTN bearing?",
        "a": "A 61901-2RS-NTN deep-groove ball bearing has a 12 mm bore, 24 mm outer diameter and 6 mm width (0.472 × 0.945 × 0.236 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 61900 compare with other series at the same 12 mm bore?",
        "a": "619 is a thin section one step above 618: 24×6 mm with a 6.0 mm radial section at 12 mm bore; a 6212 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "Are 61901 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61901 uses the same ISO 15 envelope (12×24×6 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61901?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6901LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 12×24×6 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6901LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61901-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61901-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61901-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61901",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61901-llu",
      "6901llu",
      "61901-2RS",
      "61901-2rs",
      "6901LLU",
      "61901-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61901-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6901LLB",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 24,
    "B_mm": 6,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 3.2,
    "static_load_kN": 1.46,
    "fatigue_load_limit_kN": 0.12,
    "limiting_speed_rpm": 22000,
    "max_rpm": 22000,
    "weight_g": 11,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61901-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 12 by five gives the 12 mm bore; the 24 mm outside diameter and 6 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 12 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6901LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 12 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61901 with C3 for those conditions.",
      "The 619xx thin section at 12 mm bore (6.0 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "The low-drag lip of 61901-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 61901-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 12 mm bore position before relying on it as sealed-for-life.",
      "Shaft and housing fillets must clear the bearing chamfer so the 6 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Never mix components between two 61901-RSR-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues this low-friction non-contact seal as 6901LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 12 mm bore the 61901 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61901 at 22000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 3.2 kN dynamic load rating (C) and 1.46 kN static (C0), 0.12 kN fatigue load limit Cu, 61901 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 11 g, 61901 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×24×6 mm envelope of 61901 gives a D/d ratio of 2.00 and 6.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 3.2/1.46 kN load ratings, 0.12 kN fatigue load limit Cu NTN lists the grease limiting speed at 22000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 11 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6901LLB on the 12×24×6 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61901 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61901-RSR-NTN bearing?",
        "a": "A 61901-RSR-NTN deep-groove ball bearing has a 12 mm bore, 24 mm outer diameter and 6 mm width (0.472 × 0.945 × 0.236 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What lubrication does 61901-RSR-NTN need?",
        "a": "61901-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61901 with a housing grease fitting instead."
      },
      {
        "q": "How does the 61901 bore code work?",
        "a": "The last two digits of 61901 are bore code 12, giving 12 × 5 = 12 mm bore. The 24 mm outside diameter and 6 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 61901?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6901LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 12×24×6 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61901 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6901LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61901-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61901-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61901-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61901",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61901-llb",
      "6901llb",
      "61901-RSR",
      "61901-rsr",
      "6901LLB",
      "61901-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61901-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6901ZZ",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 24,
    "B_mm": 6,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 3.2,
    "static_load_kN": 1.46,
    "fatigue_load_limit_kN": 0.12,
    "limiting_speed_rpm": 22000,
    "max_rpm": 22000,
    "weight_g": 11,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61901 carries bore code 12 = 12 mm. Outside diameter 24 mm and width 6 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6901ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Interference on a 12 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61901 with C3 clearance and re-check the residual value after mounting.",
      "The 619xx thin section (6.0 mm section height at 12 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "ZZ shields are non-contact: 61901-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61901-2RS for that.",
      "Do not wash 61901-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61900-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues the shielded version as 6901ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 12 mm bore the 61901 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61901 at 22000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 3.2 kN dynamic load rating (C) and 1.46 kN static (C0), 0.12 kN fatigue load limit Cu, 61901 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 11 g, 61901 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×24×6 mm envelope of 61901 gives a D/d ratio of 2.00 and 6.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 3.2/1.46 kN load ratings, 0.12 kN fatigue load limit Cu NTN lists the grease limiting speed at 22000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 11 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6901ZZ on the 12×24×6 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61901 in a rated drive.",
      "Standard catalogue stock of 61901 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61901 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61901-ZZ-NTN bearing?",
        "a": "A 61901-ZZ-NTN deep-groove ball bearing has a 12 mm bore, 24 mm outer diameter and 6 mm width (0.472 × 0.945 × 0.236 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What internal clearance does 61901-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61901-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61901 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61901-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 12 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 61901?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6901ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 12×24×6 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6901ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61901-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61901-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61901-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61901-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61901",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×24×6 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61901-zz",
      "6901zz",
      "61901-ZZ",
      "6901ZZ",
      "61901-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "16001",
    "brand": "NTN",
    "manufacturer_designation": "16001JRX",
    "series": "16000-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 28,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.65,
    "static_load_kN": 2.39,
    "fatigue_load_limit_kN": 0.19,
    "limiting_speed_rpm": 26000,
    "max_rpm": 26000,
    "weight_g": 19,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "16001 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the narrow 160xx section of the ISO 15 general plan, multiplying bore code 12 by five gives the 12 mm bore; the 28 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 12 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 12 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 16001 with C3 for those conditions.",
      "Because the 160xx narrow section shares the 28 mm OD of the 6012 at 12 mm bore but is only 7 mm wide, a housing machined for the wider bearing needs a spacer or relocated circlip — never assume width interchangeability.",
      "Storage matters for open bearings: 16001 leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 16000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 16001 units.",
      "Measure the shaft, do not trust the drawing: a 12 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 16001.",
      "The housing bore for the 28 mm OD should be round within IT7; an oval bore pinches the outer ring of 16001 and shows up later as two-point loaded raceway wear.",
      "The open 16001 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 12 mm bore the 16001 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 26000 r/min grease limiting speed puts 16001 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "NTN rates 16001 at 5.65 kN dynamic (C) and 2.39 kN static (C0), 0.19 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 19 g, 16001 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×28×7 mm envelope of 16001 gives a D/d ratio of 2.33 and 8.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 5.65/2.39 kN load ratings, 0.19 kN fatigue load limit Cu NTN lists the grease limiting speed at 26000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 19 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 16001JRX on the 12×28×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 16001 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 16001 is listed.",
      "Order the C3 internal-clearance version (16001 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 16001 bearing?",
        "a": "A 16001 deep-groove ball bearing has a 12 mm bore, 28 mm outer diameter and 7 mm width (0.472 × 1.102 × 0.276 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 16001 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 16001 uses the same ISO 15 envelope (12×28×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 16001 have?",
        "a": "Unless a clearance suffix says otherwise, 16001 is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 16001 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 16001?",
        "a": "NTN lists the open 16001 under the bare designation 16001JRX; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 12 mm bore envelope."
      },
      {
        "q": "Does NTN offer 16001 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 16001JRX is the correct choice."
      }
    ],
    "cross_ref": [],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "16001jrx",
      "16001",
      "16001JRX"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6001-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6001JRX",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 28,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.65,
    "static_load_kN": 2.39,
    "fatigue_load_limit_kN": 0.18,
    "limiting_speed_rpm": 26000,
    "max_rpm": 26000,
    "weight_g": 21,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6001 carries bore code 12 = 12 mm. Outside diameter 28 mm and width 8 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "At 12 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6001 against the shaft shoulder while it cools so the ring cannot creep back.",
      "Choosing the 60xx extra-light section saves radial space at 12 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6212 before committing to the smaller envelope.",
      "The open 6001-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 12×28×8 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6001-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "The housing bore for the 28 mm OD should be round within IT7; an oval bore pinches the outer ring of 6001-NTN and shows up later as two-point loaded raceway wear.",
      "The open 6001 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 12 mm bore the 6001 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 26000 r/min grease limiting speed puts 6001 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "NTN rates 6001 at 5.65 kN dynamic (C) and 2.39 kN static (C0), 0.18 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 21 g, 6001 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×28×8 mm envelope of 6001 gives a D/d ratio of 2.33 and 8.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 5.65/2.39 kN load ratings, 0.18 kN fatigue load limit Cu NTN lists the grease limiting speed at 26000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 21 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6001JRX on the 12×28×8 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6001 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6001 is listed.",
      "Standard catalogue stock of 6001 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6001-NTN bearing?",
        "a": "A 6001-NTN deep-groove ball bearing has a 12 mm bore, 28 mm outer diameter and 8 mm width (0.472 × 1.102 × 0.315 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How should 6001-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 12 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6001-NTN need?",
        "a": "The open 6001-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "What is the NTN order number for an open 6001?",
        "a": "NTN lists the open 6001 under the bare designation 6001JRX; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 12 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6001 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6001JRX is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6001-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6001-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6001-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6001",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6001jrx",
      "6001",
      "6001JRX",
      "6001-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6001-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6001JRXLLU",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 28,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.65,
    "static_load_kN": 2.39,
    "fatigue_load_limit_kN": 0.18,
    "limiting_speed_rpm": 18000,
    "max_rpm": 18000,
    "weight_g": 21,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6001 carries bore code 12 = 12 mm. Outside diameter 28 mm and width 8 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6001JRXLLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Interference on a 12 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6001 with C3 clearance and re-check the residual value after mounting.",
      "The 60xx extra-light section at 12 mm bore uses a smaller 28 mm OD than a 6212; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "Heat is the enemy of the sealed 6001-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 6001-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 28 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6001-2RS-NTN.",
      "Do not quieten a noisy bearing by preloading it: the 6000-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues the contact-sealed version as 6001JRXLLU (suffix JRXLLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 12 mm bore the 6001 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6001 at 18000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6001 at 5.65 kN dynamic (C) and 2.39 kN static (C0), 0.18 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 21 g, 6001 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×28×8 mm envelope of 6001 gives a D/d ratio of 2.33 and 8.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 5.65/2.39 kN load ratings, 0.18 kN fatigue load limit Cu NTN lists the grease limiting speed at 18000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 21 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6001JRXLLU on the 12×28×8 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6001 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6001 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6001-2RS-NTN bearing?",
        "a": "A 6001-2RS-NTN deep-groove ball bearing has a 12 mm bore, 28 mm outer diameter and 8 mm width (0.472 × 1.102 × 0.315 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What does the 2RS suffix on 6001-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "How does the 6000 compare with other series at the same 12 mm bore?",
        "a": "The second digit is the diameter series: 60 is the smallest standard section (28×8 mm, 8.0 mm radial section) at 12 mm bore — below 62/63/64 in load capacity, for light loads in compact spaces."
      },
      {
        "q": "What is the NTN suffix for a sealed 6001?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6001JRXLLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 12×28×8 mm ISO 15 envelope."
      },
      {
        "q": "Is 6001JRXLLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6001-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6001-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6001-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6001",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6001-llu",
      "6001jrxllu",
      "6001llu",
      "6001-2RS",
      "6001-2rs",
      "6001JRXLLU",
      "6001-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6001-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6001JRXLLB",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 28,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.65,
    "static_load_kN": 2.39,
    "fatigue_load_limit_kN": 0.18,
    "limiting_speed_rpm": 21000,
    "max_rpm": 21000,
    "weight_g": 21,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6001 carries bore code 12 = 12 mm. Outside diameter 28 mm and width 8 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6001JRXLLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Interference on a 12 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6001 with C3 clearance and re-check the residual value after mounting.",
      "The 60xx extra-light section at 12 mm bore uses a smaller 28 mm OD than a 6212; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "RSR low-friction seals on 6001-RSR-NTN run faster than contact-seal 6001-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6001-2RS instead.",
      "The non-contact lip of 6001-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 12 mm bore position before relying on it as sealed-for-life.",
      "A 12 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6001-RSR-NTN-C3. No clearance suffix means normal CN clearance.",
      "NTN catalogues this low-friction non-contact seal as 6001JRXLLB (suffix JRXLLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 12 mm bore the 6001 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6001 at 21000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6001 at 5.65 kN dynamic (C) and 2.39 kN static (C0), 0.18 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 21 g, 6001 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×28×8 mm envelope of 6001 gives a D/d ratio of 2.33 and 8.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 5.65/2.39 kN load ratings, 0.18 kN fatigue load limit Cu NTN lists the grease limiting speed at 21000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 21 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6001JRXLLB on the 12×28×8 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6001 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6001-RSR-NTN bearing?",
        "a": "A 6001-RSR-NTN deep-groove ball bearing has a 12 mm bore, 28 mm outer diameter and 8 mm width (0.472 × 1.102 × 0.315 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What internal clearance does 6001-RSR-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6001-RSR-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6001 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6001-RSR-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 12 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 6001?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6001JRXLLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 12×28×8 mm ISO 15 envelope."
      },
      {
        "q": "Is 6001JRXLLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6001-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6001-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6001-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6001",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6001-llb",
      "6001jrxllb",
      "6001llb",
      "6001-RSR",
      "6001-rsr",
      "6001JRXLLB",
      "6001-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6001-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6001JRXZZ",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 28,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.65,
    "static_load_kN": 2.39,
    "fatigue_load_limit_kN": 0.18,
    "limiting_speed_rpm": 21000,
    "max_rpm": 21000,
    "weight_g": 21,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6001 carries bore code 12 = 12 mm. Outside diameter 28 mm and width 8 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6001JRXZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At 12 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6001 against the shaft shoulder while it cools so the ring cannot creep back.",
      "Choosing the 60xx extra-light section saves radial space at 12 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6212 before committing to the smaller envelope.",
      "ZZ shields are non-contact: 6001-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6001-2RS for that.",
      "Do not wash 6001-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 8 mm-wide ring of 6001-ZZ-NTN drags the lip and overheats it.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues the shielded version as 6001JRXZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 12 mm bore the 6001 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6001 at 21000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6001 at 5.65 kN dynamic (C) and 2.39 kN static (C0), 0.18 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 21 g, 6001 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×28×8 mm envelope of 6001 gives a D/d ratio of 2.33 and 8.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 5.65/2.39 kN load ratings, 0.18 kN fatigue load limit Cu NTN lists the grease limiting speed at 21000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 21 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6001JRXZZ on the 12×28×8 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6001 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6001 is listed.",
      "Order the C3 internal-clearance version (6001 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6001-ZZ-NTN bearing?",
        "a": "A 6001-ZZ-NTN deep-groove ball bearing has a 12 mm bore, 28 mm outer diameter and 8 mm width (0.472 × 1.102 × 0.315 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How should 6001-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 12 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6001-ZZ-NTN need?",
        "a": "6001-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "What is the NTN suffix for a sealed 6001?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6001JRXZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 12×28×8 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6001JRXZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6001-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6001-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6001-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6001-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6001",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×28×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6001-zz",
      "6001jrxzz",
      "6001zz",
      "6001-ZZ",
      "6001JRXZZ",
      "6001-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6201-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6201",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 32,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 6.75,
    "static_load_kN": 2.75,
    "fatigue_load_limit_kN": 0.21,
    "limiting_speed_rpm": 22000,
    "max_rpm": 22000,
    "weight_g": 37,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6201 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 12 by five gives the 12 mm bore; the 32 mm outside diameter and 10 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 12 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Interference on a 12 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6201 with C3 clearance and re-check the residual value after mounting.",
      "The 62xx light series is the default general-purpose section at 12 mm bore; before upgrading to a 6312 for extra capacity, confirm the housing accepts a 32 mm OD and 10 mm width — it is not a drop-in swap.",
      "The open 6201-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 12×32×10 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 6200-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6201 units.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 10 mm-wide ring of 6201-NTN drags the lip and overheats it.",
      "The open 6201 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 12 mm bore the 6201 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6201 at 22000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 6201 at 6.75 kN dynamic (C) and 2.75 kN static (C0), 0.21 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 37 g, 6201 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×32×10 mm envelope of 6201 gives a D/d ratio of 2.67 and 10.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 6.75/2.75 kN load ratings, 0.21 kN fatigue load limit Cu NTN lists the grease limiting speed at 22000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 37 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6201 on the 12×32×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6201 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6201 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6201-NTN bearing?",
        "a": "A 6201-NTN deep-groove ball bearing has a 12 mm bore, 32 mm outer diameter and 10 mm width (0.472 × 1.26 × 0.394 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 6201 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6201 uses the same ISO 15 envelope (12×32×10 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 6201-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6201-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6201 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 6201?",
        "a": "NTN lists the open 6201 under the bare designation 6201; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 12 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6201 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6201 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6201-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6201-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6201-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6201",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6201",
      "6201-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6201-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6201LLU",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 32,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 6.75,
    "static_load_kN": 2.75,
    "fatigue_load_limit_kN": 0.21,
    "limiting_speed_rpm": 16000,
    "max_rpm": 16000,
    "weight_g": 37,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6201 carries bore code 12 = 12 mm. Outside diameter 32 mm and width 10 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6201LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Interference on a 12 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6201 with C3 clearance and re-check the residual value after mounting.",
      "At 12 mm bore the 62xx light series is the workhorse section; its 32×10 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "Heat is the enemy of the sealed 6201-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 6201-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "A 12 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 10 mm-wide ring of 6201-2RS-NTN drags the lip and overheats it.",
      "NTN catalogues the contact-sealed version as 6201LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 12 mm bore the 6201 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6201 at 16000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6201 at 6.75 kN dynamic (C) and 2.75 kN static (C0), 0.21 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 37 g, 6201 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×32×10 mm envelope of 6201 gives a D/d ratio of 2.67 and 10.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 6.75/2.75 kN load ratings, 0.21 kN fatigue load limit Cu NTN lists the grease limiting speed at 16000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 37 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6201LLU on the 12×32×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6201 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Standard catalogue stock of 6201 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6201-2RS-NTN bearing?",
        "a": "A 6201-2RS-NTN deep-groove ball bearing has a 12 mm bore, 32 mm outer diameter and 10 mm width (0.472 × 1.26 × 0.394 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "Are 6201 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6201 uses the same ISO 15 envelope (12×32×10 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 6201-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6201-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6201 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 6201?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6201LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 12×32×10 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6201 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6201LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6201-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6201-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6201-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6201",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6201-llu",
      "6201llu",
      "6201-2RS",
      "6201-2rs",
      "6201LLU",
      "6201-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6201-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6201LLB",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 32,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 6.75,
    "static_load_kN": 2.75,
    "fatigue_load_limit_kN": 0.21,
    "limiting_speed_rpm": 20000,
    "max_rpm": 20000,
    "weight_g": 37,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6201 carries bore code 12 = 12 mm. Outside diameter 32 mm and width 10 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6201LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "At 12 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6201 against the shaft shoulder while it cools so the ring cannot creep back.",
      "At 12 mm bore the 62xx light series is the workhorse section; its 32×10 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "The low-drag lip of 6201-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 6201-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 12 mm bore position before relying on it as sealed-for-life.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6201-RSR-NTN-C3. No clearance suffix means normal CN clearance.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 10 mm-wide ring of 6201-RSR-NTN drags the lip and overheats it.",
      "NTN catalogues this low-friction non-contact seal as 6201LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 12 mm bore the 6201 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6201 at 20000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6201 at 6.75 kN dynamic (C) and 2.75 kN static (C0), 0.21 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 37 g, 6201 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×32×10 mm envelope of 6201 gives a D/d ratio of 2.67 and 10.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 6.75/2.75 kN load ratings, 0.21 kN fatigue load limit Cu NTN lists the grease limiting speed at 20000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 37 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6201LLB on the 12×32×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6201 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6201 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6201-RSR-NTN bearing?",
        "a": "A 6201-RSR-NTN deep-groove ball bearing has a 12 mm bore, 32 mm outer diameter and 10 mm width (0.472 × 1.26 × 0.394 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "Are 6201 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6201 uses the same ISO 15 envelope (12×32×10 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 6201-RSR-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6201-RSR-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6201 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 6201?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6201LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 12×32×10 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6201 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6201LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6201-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6201-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6201-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6201",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6201-llb",
      "6201llb",
      "6201-RSR",
      "6201-rsr",
      "6201LLB",
      "6201-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6201-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6201ZZ",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 32,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 6.75,
    "static_load_kN": 2.75,
    "fatigue_load_limit_kN": 0.21,
    "limiting_speed_rpm": 20000,
    "max_rpm": 20000,
    "weight_g": 37,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6201 carries bore code 12 = 12 mm. Outside diameter 32 mm and width 10 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6201ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 12 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6201 with C3 for those conditions.",
      "At 12 mm bore the 62xx light series is the workhorse section; its 32×10 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "Do not wash 6201-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6201-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Measure the shaft, do not trust the drawing: a 12 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6201-ZZ-NTN.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 10 mm-wide ring of 6201-ZZ-NTN drags the lip and overheats it.",
      "NTN catalogues the shielded version as 6201ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 12 mm bore the 6201 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6201 at 20000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6201 at 6.75 kN dynamic (C) and 2.75 kN static (C0), 0.21 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 37 g, 6201 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 12×32×10 mm envelope of 6201 gives a D/d ratio of 2.67 and 10.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 6.75/2.75 kN load ratings, 0.21 kN fatigue load limit Cu NTN lists the grease limiting speed at 20000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 37 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6201ZZ on the 12×32×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6201 in a rated drive.",
      "Order the C3 internal-clearance version (6201 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6201-ZZ-NTN bearing?",
        "a": "A 6201-ZZ-NTN deep-groove ball bearing has a 12 mm bore, 32 mm outer diameter and 10 mm width (0.472 × 1.26 × 0.394 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 6201 bore code work?",
        "a": "The last two digits of 6201 are bore code 12, giving 12 × 5 = 12 mm bore. The 32 mm outside diameter and 10 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the ZZ suffix on 6201-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "What is the NTN suffix for a sealed 6201?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6201ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 12×32×10 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6201 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6201ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6201-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6201-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6201-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6201-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6201",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×32×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6201-zz",
      "6201zz",
      "6201-ZZ",
      "6201ZZ",
      "6201-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6301-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6301",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 37,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.8,
    "static_load_kN": 4.2,
    "fatigue_load_limit_kN": 0.33,
    "limiting_speed_rpm": 20000,
    "max_rpm": 20000,
    "weight_g": 60,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6301 carries bore code 12 = 12 mm. Outside diameter 37 mm and width 12 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Interference on a 12 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6301 with C3 clearance and re-check the residual value after mounting.",
      "The 63xx medium section at 12 mm bore gains dynamic rating through larger rolling elements on a 37 mm OD; the penalty is mass and a lower limiting speed than the 6212 — do not specify it for speed-critical shafts.",
      "Storage matters for open bearings: 6301-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 6300-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6301 units.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6301-NTN-C3. No clearance suffix means normal CN clearance.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6300-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "The open 6301 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 12 mm bore the 6301 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6301 at 20000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 6301 at 10.8 kN dynamic (C) and 4.2 kN static (C0), 0.33 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 60 g, 6301 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 12×37×12 mm envelope of 6301 gives a D/d ratio of 3.08 and 12.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 10.8/4.2 kN load ratings, 0.33 kN fatigue load limit Cu NTN lists the grease limiting speed at 20000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 60 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6301 on the 12×37×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6301 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6301-NTN bearing?",
        "a": "A 6301-NTN deep-groove ball bearing has a 12 mm bore, 37 mm outer diameter and 12 mm width (0.472 × 1.457 × 0.472 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What internal clearance does 6301-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6301-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6301 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6301-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 12 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN order number for an open 6301?",
        "a": "NTN lists the open 6301 under the bare designation 6301; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 12 mm bore envelope."
      },
      {
        "q": "Is 6301 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6301-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6301-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6301-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6301",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6301",
      "6301-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6301-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6301LLU",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 37,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.8,
    "static_load_kN": 4.2,
    "fatigue_load_limit_kN": 0.33,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "weight_g": 60,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6301 carries bore code 12 = 12 mm. Outside diameter 37 mm and width 12 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6301LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Interference on a 12 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6301 with C3 clearance and re-check the residual value after mounting.",
      "The 63xx medium section at 12 mm bore gains dynamic rating through larger rolling elements on a 37 mm OD; the penalty is mass and a lower limiting speed than the 6212 — do not specify it for speed-critical shafts.",
      "Heat is the enemy of the sealed 6301-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 6301-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Vibration during standstill brinells the raceways of a 12 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "A 12 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues the contact-sealed version as 6301LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 12 mm bore the 6301 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6301 at 15000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6301 at 10.8 kN dynamic (C) and 4.2 kN static (C0), 0.33 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 60 g, 6301 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 12×37×12 mm envelope of 6301 gives a D/d ratio of 3.08 and 12.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 10.8/4.2 kN load ratings, 0.33 kN fatigue load limit Cu NTN lists the grease limiting speed at 15000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 60 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6301LLU on the 12×37×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6301 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Order the C3 internal-clearance version (6301 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6301-2RS-NTN bearing?",
        "a": "A 6301-2RS-NTN deep-groove ball bearing has a 12 mm bore, 37 mm outer diameter and 12 mm width (0.472 × 1.457 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What internal clearance does 6301-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6301-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6301 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6301-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 12 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 6301?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6301LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 12×37×12 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6301 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6301LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6301-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6301-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6301-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6301",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6301-llu",
      "6301llu",
      "6301-2RS",
      "6301-2rs",
      "6301LLU",
      "6301-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6301-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6301LLB",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 37,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.8,
    "static_load_kN": 4.2,
    "fatigue_load_limit_kN": 0.33,
    "limiting_speed_rpm": 19000,
    "max_rpm": 19000,
    "weight_g": 60,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6301-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 12 by five gives the 12 mm bore; the 37 mm outside diameter and 12 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 12 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6301LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Interference on a 12 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6301 with C3 clearance and re-check the residual value after mounting.",
      "The 63xx medium section at 12 mm bore gains dynamic rating through larger rolling elements on a 37 mm OD; the penalty is mass and a lower limiting speed than the 6212 — do not specify it for speed-critical shafts.",
      "RSR low-friction seals on 6301-RSR-NTN run faster than contact-seal 6301-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6301-2RS instead.",
      "The low-drag lip of 6301-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 37 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6301-RSR-NTN.",
      "Shaft and housing fillets must clear the bearing chamfer so the 12 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues this low-friction non-contact seal as 6301LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 12 mm bore the 6301 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6301 at 19000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6301 at 10.8 kN dynamic (C) and 4.2 kN static (C0), 0.33 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 60 g, 6301 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 12×37×12 mm envelope of 6301 gives a D/d ratio of 3.08 and 12.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 10.8/4.2 kN load ratings, 0.33 kN fatigue load limit Cu NTN lists the grease limiting speed at 19000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 60 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6301LLB on the 12×37×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6301 in a rated drive.",
      "Order the C3 internal-clearance version (6301 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Standard catalogue stock of 6301 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6301-RSR-NTN bearing?",
        "a": "A 6301-RSR-NTN deep-groove ball bearing has a 12 mm bore, 37 mm outer diameter and 12 mm width (0.472 × 1.457 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How should 6301-RSR-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 12 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6301-RSR-NTN need?",
        "a": "6301-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6301 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 6301?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6301LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 12×37×12 mm ISO 15 envelope."
      },
      {
        "q": "Is 6301LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6301-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6301-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6301-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6301",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6301-llb",
      "6301llb",
      "6301-RSR",
      "6301-rsr",
      "6301LLB",
      "6301-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6301-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6301ZZ",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 12,
    "D_mm": 37,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.8,
    "static_load_kN": 4.2,
    "fatigue_load_limit_kN": 0.33,
    "limiting_speed_rpm": 19000,
    "max_rpm": 19000,
    "weight_g": 60,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6301-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 12 by five gives the 12 mm bore; the 37 mm outside diameter and 12 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 12 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6301ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At 12 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6301 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 63xx medium section at 12 mm bore gains dynamic rating through larger rolling elements on a 37 mm OD; the penalty is mass and a lower limiting speed than the 6212 — do not specify it for speed-critical shafts.",
      "ZZ shields are non-contact: 6301-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6301-2RS for that.",
      "Do not wash 6301-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Never mix components between two 6301-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the shielded version as 6301ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 12 mm bore the 6301 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6301 at 19000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6301 at 10.8 kN dynamic (C) and 4.2 kN static (C0), 0.33 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 60 g, 6301 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 12×37×12 mm envelope of 6301 gives a D/d ratio of 3.08 and 12.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 10.8/4.2 kN load ratings, 0.33 kN fatigue load limit Cu NTN lists the grease limiting speed at 19000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 60 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6301ZZ on the 12×37×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6301 in a rated drive.",
      "Standard catalogue stock of 6301 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6301-ZZ-NTN bearing?",
        "a": "A 6301-ZZ-NTN deep-groove ball bearing has a 12 mm bore, 37 mm outer diameter and 12 mm width (0.472 × 1.457 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 6300 compare with other series at the same 12 mm bore?",
        "a": "The '3' is the medium diameter series: 37×12 mm, 12.5 mm radial section at 12 mm bore, carrying more load than a 6212 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "Are 6301 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6301 uses the same ISO 15 envelope (12×37×12 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6301?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6301ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 12×37×12 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6301 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6301ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6301-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6301-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6301-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6301-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6301",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 12×37×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6301-zz",
      "6301zz",
      "6301-ZZ",
      "6301ZZ",
      "6301-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61802-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6802",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 24,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.3,
    "static_load_kN": 1.26,
    "fatigue_load_limit_kN": 0.09,
    "limiting_speed_rpm": 26000,
    "max_rpm": 26000,
    "weight_g": 7,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61802 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 15 by five gives the 15 mm bore; the 24 mm outside diameter and 5 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 15 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Interference on a 15 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61802 with C3 clearance and re-check the residual value after mounting.",
      "Only 4.5 mm of radial section separates bore and OD on the 618xx series at 15 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6215.",
      "Storage matters for open bearings: 61802-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 61800-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61802 units.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 24 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61802-NTN.",
      "Do not quieten a noisy bearing by preloading it: the 61800-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "The open 61802 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 15 mm bore the 61802 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 26000 r/min grease limiting speed puts 61802 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "At 2.3 kN dynamic load rating (C) and 1.26 kN static (C0), 0.09 kN fatigue load limit Cu, 61802 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 7 g, 61802 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×24×5 mm envelope of 61802 gives a D/d ratio of 1.60 and 4.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 2.3/1.26 kN load ratings, 0.09 kN fatigue load limit Cu NTN lists the grease limiting speed at 26000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 7 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6802 on the 15×24×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61802 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61802 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61802-NTN bearing?",
        "a": "A 61802-NTN deep-groove ball bearing has a 15 mm bore, 24 mm outer diameter and 5 mm width (0.591 × 0.945 × 0.197 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 61800 compare with other series at the same 15 mm bore?",
        "a": "618 is an extra-thin section: 24×5 mm, only 4.5 mm radial section at 15 mm bore, far smaller than a 6215, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "Are 61802 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61802 uses the same ISO 15 envelope (15×24×5 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 61802?",
        "a": "NTN lists the open 61802 under the bare designation 6802; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 15 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6802?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61802-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61802-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61802-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6802",
      "61802",
      "61802-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61802-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6802LLU",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 24,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.3,
    "static_load_kN": 1.26,
    "fatigue_load_limit_kN": 0.09,
    "limiting_speed_rpm": 17000,
    "max_rpm": 17000,
    "weight_g": 7,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61802-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 15 by five gives the 15 mm bore; the 24 mm outside diameter and 5 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 15 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6802LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 15 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61802 with C3 for those conditions.",
      "Only 4.5 mm of radial section separates bore and OD on the 618xx series at 15 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6215.",
      "Contact seals add drag and heat: 61802-2RS-NTN runs slower and cooler-limited than the open 61802; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 61802-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 24 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61802-2RS-NTN.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61802-2RS-NTN-C3. No clearance suffix means normal CN clearance.",
      "NTN catalogues the contact-sealed version as 6802LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 15 mm bore the 61802 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61802 at 17000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 2.3 kN dynamic load rating (C) and 1.26 kN static (C0), 0.09 kN fatigue load limit Cu, 61802 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 7 g, 61802 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×24×5 mm envelope of 61802 gives a D/d ratio of 1.60 and 4.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 2.3/1.26 kN load ratings, 0.09 kN fatigue load limit Cu NTN lists the grease limiting speed at 17000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 7 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6802LLU on the 15×24×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61802 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61802 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61802-2RS-NTN bearing?",
        "a": "A 61802-2RS-NTN deep-groove ball bearing has a 15 mm bore, 24 mm outer diameter and 5 mm width (0.591 × 0.945 × 0.197 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What internal clearance does 61802-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61802-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61802 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61802-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 15 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 61802?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6802LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 15×24×5 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6802LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61802-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61802-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61802-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61802-llu",
      "6802llu",
      "61802-2RS",
      "61802-2rs",
      "6802LLU",
      "61802-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61802-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6802LLB",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 24,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.3,
    "static_load_kN": 1.26,
    "fatigue_load_limit_kN": 0.09,
    "limiting_speed_rpm": 26000,
    "max_rpm": 26000,
    "weight_g": 7,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61802 carries bore code 15 = 15 mm. Outside diameter 24 mm and width 5 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 15 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6802LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At 15 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61802 against the shaft shoulder while it cools so the ring cannot creep back.",
      "Only 4.5 mm of radial section separates bore and OD on the 618xx series at 15 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6215.",
      "RSR low-friction seals on 61802-RSR-NTN run faster than contact-seal 61802-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61802-2RS instead.",
      "The non-contact lip of 61802-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 15 mm bore position before relying on it as sealed-for-life.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 5 mm-wide ring of 61802-RSR-NTN drags the lip and overheats it.",
      "The housing bore for the 24 mm OD should be round within IT7; an oval bore pinches the outer ring of 61802-RSR-NTN and shows up later as two-point loaded raceway wear.",
      "NTN catalogues this low-friction non-contact seal as 6802LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 15 mm bore the 61802 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 26000 r/min grease limiting speed puts 61802 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "At 2.3 kN dynamic load rating (C) and 1.26 kN static (C0), 0.09 kN fatigue load limit Cu, 61802 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 7 g, 61802 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×24×5 mm envelope of 61802 gives a D/d ratio of 1.60 and 4.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 2.3/1.26 kN load ratings, 0.09 kN fatigue load limit Cu NTN lists the grease limiting speed at 26000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 7 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6802LLB on the 15×24×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61802 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61802-RSR-NTN bearing?",
        "a": "A 61802-RSR-NTN deep-groove ball bearing has a 15 mm bore, 24 mm outer diameter and 5 mm width (0.591 × 0.945 × 0.197 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What lubrication does 61802-RSR-NTN need?",
        "a": "61802-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61802 with a housing grease fitting instead."
      },
      {
        "q": "How does the 61802 bore code work?",
        "a": "The last two digits of 61802 are bore code 15, giving 15 × 5 = 15 mm bore. The 24 mm outside diameter and 5 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 61802?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6802LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 15×24×5 mm ISO 15 envelope."
      },
      {
        "q": "Is 6802LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61802-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61802-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61802-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61802-llb",
      "6802llb",
      "61802-RSR",
      "61802-rsr",
      "6802LLB",
      "61802-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61802-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6802ZZ",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 24,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.3,
    "static_load_kN": 1.26,
    "fatigue_load_limit_kN": 0.09,
    "limiting_speed_rpm": 26000,
    "max_rpm": 26000,
    "weight_g": 7,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61802-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 15 by five gives the 15 mm bore; the 24 mm outside diameter and 5 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 15 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6802ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Interference on a 15 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61802 with C3 clearance and re-check the residual value after mounting.",
      "Only 4.5 mm of radial section separates bore and OD on the 618xx series at 15 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6215.",
      "ZZ shields are non-contact: 61802-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61802-2RS for that.",
      "Shielded 61802-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "A 15 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Do not quieten a noisy bearing by preloading it: the 61800-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues the shielded version as 6802ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 15 mm bore the 61802 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "The 26000 r/min grease limiting speed puts 61802 in NTN's high-speed range; at these speeds relubrication interval shortens sharply and the pressed-steel cage must be checked for cage-bar critical speed.",
      "At 2.3 kN dynamic load rating (C) and 1.26 kN static (C0), 0.09 kN fatigue load limit Cu, 61802 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 7 g, 61802 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×24×5 mm envelope of 61802 gives a D/d ratio of 1.60 and 4.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 2.3/1.26 kN load ratings, 0.09 kN fatigue load limit Cu NTN lists the grease limiting speed at 26000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 7 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6802ZZ on the 15×24×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61802 in a rated drive.",
      "Standard catalogue stock of 61802 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Order the C3 internal-clearance version (61802 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61802-ZZ-NTN bearing?",
        "a": "A 61802-ZZ-NTN deep-groove ball bearing has a 15 mm bore, 24 mm outer diameter and 5 mm width (0.591 × 0.945 × 0.197 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How should 61802-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 15 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 61802-ZZ-NTN need?",
        "a": "61802-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "What is the NTN suffix for a sealed 61802?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6802ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 15×24×5 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61802 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6802ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61802-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61802-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61802-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61802-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×24×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61802-zz",
      "6802zz",
      "61802-ZZ",
      "6802ZZ",
      "61802-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61902-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6902",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 28,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 4.05,
    "static_load_kN": 2,
    "fatigue_load_limit_kN": 0.16,
    "limiting_speed_rpm": 24000,
    "max_rpm": 24000,
    "weight_g": 16,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61902 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 15 by five gives the 15 mm bore; the 28 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 15 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At 15 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61902 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 619xx thin section (6.5 mm section height at 15 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "The open 61902-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 15×28×7 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 61900-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61902 units.",
      "Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61900-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "The open 61902 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 15 mm bore the 61902 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61902 at 24000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "At 4.05 kN dynamic load rating (C) and 2 kN static (C0), 0.16 kN fatigue load limit Cu, 61902 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 16 g, 61902 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×28×7 mm envelope of 61902 gives a D/d ratio of 1.87 and 6.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 4.05/2 kN load ratings, 0.16 kN fatigue load limit Cu NTN lists the grease limiting speed at 24000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 16 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6902 on the 15×28×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61902 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61902 is listed.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61902-NTN bearing?",
        "a": "A 61902-NTN deep-groove ball bearing has a 15 mm bore, 28 mm outer diameter and 7 mm width (0.591 × 1.102 × 0.276 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 61902 bore code work?",
        "a": "The last two digits of 61902 are bore code 15, giving 15 × 5 = 15 mm bore. The 28 mm outside diameter and 7 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does no suffix on 61902 mean?",
        "a": "A bare 61902 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "What is the NTN order number for an open 61902?",
        "a": "NTN lists the open 61902 under the bare designation 6902; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 15 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6902?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61902-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61902-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61902-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61902",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6902",
      "61902",
      "61902-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61902-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6902LLU",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 28,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 4.05,
    "static_load_kN": 2,
    "fatigue_load_limit_kN": 0.16,
    "limiting_speed_rpm": 16000,
    "max_rpm": 16000,
    "weight_g": 16,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61902-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 15 by five gives the 15 mm bore; the 28 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 15 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6902LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "At 15 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61902 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 619xx thin section at 15 mm bore (6.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "Contact seals add drag and heat: 61902-2RS-NTN runs slower and cooler-limited than the open 61902; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 61902-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Measure the shaft, do not trust the drawing: a 15 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61902-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6902LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 15 mm bore the 61902 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61902 at 16000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 4.05 kN dynamic load rating (C) and 2 kN static (C0), 0.16 kN fatigue load limit Cu, 61902 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 16 g, 61902 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×28×7 mm envelope of 61902 gives a D/d ratio of 1.87 and 6.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 4.05/2 kN load ratings, 0.16 kN fatigue load limit Cu NTN lists the grease limiting speed at 16000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 16 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6902LLU on the 15×28×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61902 in a rated drive.",
      "Order the C3 internal-clearance version (61902 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61902-2RS-NTN bearing?",
        "a": "A 61902-2RS-NTN deep-groove ball bearing has a 15 mm bore, 28 mm outer diameter and 7 mm width (0.591 × 1.102 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What internal clearance does 61902-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61902-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61902 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61902-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 15 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 61902?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6902LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 15×28×7 mm ISO 15 envelope."
      },
      {
        "q": "Is 6902LLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61902-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61902-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61902-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61902",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61902-llu",
      "6902llu",
      "61902-2RS",
      "61902-2rs",
      "6902LLU",
      "61902-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61902-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6902LLB",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 28,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 4.05,
    "static_load_kN": 2,
    "fatigue_load_limit_kN": 0.16,
    "limiting_speed_rpm": 24000,
    "max_rpm": 24000,
    "weight_g": 16,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61902 carries bore code 15 = 15 mm. Outside diameter 28 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 15 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6902LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "At 15 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61902 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 619xx thin section (6.5 mm section height at 15 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "RSR low-friction seals on 61902-RSR-NTN run faster than contact-seal 61902-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61902-2RS instead.",
      "The non-contact lip of 61902-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 15 mm bore position before relying on it as sealed-for-life.",
      "Measure the shaft, do not trust the drawing: a 15 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61902-RSR-NTN.",
      "Shaft and housing fillets must clear the bearing chamfer so the 7 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues this low-friction non-contact seal as 6902LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 15 mm bore the 61902 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61902 at 24000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 4.05 kN dynamic load rating (C) and 2 kN static (C0), 0.16 kN fatigue load limit Cu, 61902 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 16 g, 61902 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×28×7 mm envelope of 61902 gives a D/d ratio of 1.87 and 6.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 4.05/2 kN load ratings, 0.16 kN fatigue load limit Cu NTN lists the grease limiting speed at 24000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 16 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6902LLB on the 15×28×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61902 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61902-RSR-NTN bearing?",
        "a": "A 61902-RSR-NTN deep-groove ball bearing has a 15 mm bore, 28 mm outer diameter and 7 mm width (0.591 × 1.102 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What lubrication does 61902-RSR-NTN need?",
        "a": "61902-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61902 with a housing grease fitting instead."
      },
      {
        "q": "How does the 61902 bore code work?",
        "a": "The last two digits of 61902 are bore code 15, giving 15 × 5 = 15 mm bore. The 28 mm outside diameter and 7 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 61902?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6902LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 15×28×7 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6902LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61902-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61902-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61902-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61902",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61902-llb",
      "6902llb",
      "61902-RSR",
      "61902-rsr",
      "6902LLB",
      "61902-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61902-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6902ZZ",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 28,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 4.05,
    "static_load_kN": 2,
    "fatigue_load_limit_kN": 0.16,
    "limiting_speed_rpm": 24000,
    "max_rpm": 24000,
    "weight_g": 16,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61902-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 15 by five gives the 15 mm bore; the 28 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 15 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6902ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At 15 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61902 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 619xx thin section at 15 mm bore (6.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "ZZ shields are non-contact: 61902-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61902-2RS for that.",
      "Shielded 61902-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Measure the shaft, do not trust the drawing: a 15 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61902-ZZ-NTN.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61902-ZZ-NTN-C3. No clearance suffix means normal CN clearance.",
      "NTN catalogues the shielded version as 6902ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 15 mm bore the 61902 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61902 at 24000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 4.05 kN dynamic load rating (C) and 2 kN static (C0), 0.16 kN fatigue load limit Cu, 61902 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 16 g, 61902 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×28×7 mm envelope of 61902 gives a D/d ratio of 1.87 and 6.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 4.05/2 kN load ratings, 0.16 kN fatigue load limit Cu NTN lists the grease limiting speed at 24000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 16 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6902ZZ on the 15×28×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61902 in a rated drive.",
      "Standard catalogue stock of 61902 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61902-ZZ-NTN bearing?",
        "a": "A 61902-ZZ-NTN deep-groove ball bearing has a 15 mm bore, 28 mm outer diameter and 7 mm width (0.591 × 1.102 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "Are 61902 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61902 uses the same ISO 15 envelope (15×28×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 61902-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61902-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61902 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 61902?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6902ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 15×28×7 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6902ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61902-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61902-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61902-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61902-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61902",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×28×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61902-zz",
      "6902zz",
      "61902-ZZ",
      "6902ZZ",
      "61902-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "16002-NTN",
    "brand": "NTN",
    "manufacturer_designation": "16002",
    "series": "16000-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 32,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 6.2,
    "static_load_kN": 2.84,
    "fatigue_load_limit_kN": 0.22,
    "limiting_speed_rpm": 22000,
    "max_rpm": 22000,
    "weight_g": 25,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 16000-series (the narrow extra-light section of ISO 15) the last two digits encode the bore: 16002 carries bore code 15 = 15 mm. Outside diameter 32 mm and width 8 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 15 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "At 15 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 16002 against the shaft shoulder while it cools so the ring cannot creep back.",
      "Because the 160xx narrow section shares the 32 mm OD of the 6015 at 15 mm bore but is only 8 mm wide, a housing machined for the wider bearing needs a spacer or relocated circlip — never assume width interchangeability.",
      "Storage matters for open bearings: 16002-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 16000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 16002 units.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 16002-NTN-C3. No clearance suffix means normal CN clearance.",
      "Never mix components between two 16002-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "The open 16002 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 15 mm bore the 16002 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 16002 at 22000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 16002 at 6.2 kN dynamic (C) and 2.84 kN static (C0), 0.22 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 25 g, 16002 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×32×8 mm envelope of 16002 gives a D/d ratio of 2.13 and 8.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 6.2/2.84 kN load ratings, 0.22 kN fatigue load limit Cu NTN lists the grease limiting speed at 22000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 25 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 16002 on the 15×32×8 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 16002 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 16002 is listed.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 16002-NTN bearing?",
        "a": "A 16002-NTN deep-groove ball bearing has a 15 mm bore, 32 mm outer diameter and 8 mm width (0.591 × 1.26 × 0.315 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 16002 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 16002 uses the same ISO 15 envelope (15×32×8 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 16002-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 16002-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 16002 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 16002?",
        "a": "NTN lists the open 16002 under the bare designation 16002; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 15 mm bore envelope."
      },
      {
        "q": "Does NTN offer 16002 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 16002 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "16002",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 15×32×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "16002-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×32×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "16002",
      "16002-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6002-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6002",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 32,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 6.2,
    "static_load_kN": 2.84,
    "fatigue_load_limit_kN": 0.2,
    "limiting_speed_rpm": 22000,
    "max_rpm": 22000,
    "weight_g": 30,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6002 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 15 by five gives the 15 mm bore; the 32 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 15 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At 15 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6002 against the shaft shoulder while it cools so the ring cannot creep back.",
      "Choosing the 60xx extra-light section saves radial space at 15 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6215 before committing to the smaller envelope.",
      "The open 6002-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 15×32×9 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6002-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "The housing bore for the 32 mm OD should be round within IT7; an oval bore pinches the outer ring of 6002-NTN and shows up later as two-point loaded raceway wear.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 9 mm-wide ring of 6002-NTN drags the lip and overheats it.",
      "The open 6002 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 15 mm bore the 6002 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6002 at 22000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 6002 at 6.2 kN dynamic (C) and 2.84 kN static (C0), 0.2 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 30 g, 6002 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×32×9 mm envelope of 6002 gives a D/d ratio of 2.13 and 8.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 6.2/2.84 kN load ratings, 0.2 kN fatigue load limit Cu NTN lists the grease limiting speed at 22000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 30 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6002 on the 15×32×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6002 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6002 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6002-NTN bearing?",
        "a": "A 6002-NTN deep-groove ball bearing has a 15 mm bore, 32 mm outer diameter and 9 mm width (0.591 × 1.26 × 0.354 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What internal clearance does 6002-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6002-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6002 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6002-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 15 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN order number for an open 6002?",
        "a": "NTN lists the open 6002 under the bare designation 6002; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 15 mm bore envelope."
      },
      {
        "q": "Is 6002 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6002-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6002-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6002-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6002",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6002",
      "6002-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6002-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6002LLU",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 32,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 6.2,
    "static_load_kN": 2.84,
    "fatigue_load_limit_kN": 0.2,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "weight_g": 30,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6002-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 15 by five gives the 15 mm bore; the 32 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 15 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6002LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 15 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6002 with C3 for those conditions.",
      "The 60xx extra-light section at 15 mm bore uses a smaller 32 mm OD than a 6215; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "Contact seals add drag and heat: 6002-2RS-NTN runs slower and cooler-limited than the open 6002; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 6002-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never mix components between two 6002-2RS-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Measure the shaft, do not trust the drawing: a 15 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6002-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6002LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 15 mm bore the 6002 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6002 at 15000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6002 at 6.2 kN dynamic (C) and 2.84 kN static (C0), 0.2 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 30 g, 6002 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×32×9 mm envelope of 6002 gives a D/d ratio of 2.13 and 8.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 6.2/2.84 kN load ratings, 0.2 kN fatigue load limit Cu NTN lists the grease limiting speed at 15000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 30 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6002LLU on the 15×32×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6002 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6002 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6002-2RS-NTN bearing?",
        "a": "A 6002-2RS-NTN deep-groove ball bearing has a 15 mm bore, 32 mm outer diameter and 9 mm width (0.591 × 1.26 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 6000 compare with other series at the same 15 mm bore?",
        "a": "The second digit is the diameter series: 60 is the smallest standard section (32×9 mm, 8.5 mm radial section) at 15 mm bore — below 62/63/64 in load capacity, for light loads in compact spaces."
      },
      {
        "q": "Are 6002 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6002 uses the same ISO 15 envelope (15×32×9 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6002?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6002LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 15×32×9 mm ISO 15 envelope."
      },
      {
        "q": "Is 6002LLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6002-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6002-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6002-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6002",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6002-llu",
      "6002llu",
      "6002-2RS",
      "6002-2rs",
      "6002LLU",
      "6002-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6002-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6002LLB",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 32,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 6.2,
    "static_load_kN": 2.84,
    "fatigue_load_limit_kN": 0.2,
    "limiting_speed_rpm": 18000,
    "max_rpm": 18000,
    "weight_g": 30,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6002 carries bore code 15 = 15 mm. Outside diameter 32 mm and width 9 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 15 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6002LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "conveyor drives",
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 15 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6002 with C3 for those conditions.",
      "The 60xx extra-light section at 15 mm bore uses a smaller 32 mm OD than a 6215; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "RSR low-friction seals on 6002-RSR-NTN run faster than contact-seal 6002-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6002-2RS instead.",
      "The non-contact lip of 6002-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 15 mm bore position before relying on it as sealed-for-life.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Shaft and housing fillets must clear the bearing chamfer so the 9 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues this low-friction non-contact seal as 6002LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 15 mm bore the 6002 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6002 at 18000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6002 at 6.2 kN dynamic (C) and 2.84 kN static (C0), 0.2 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 30 g, 6002 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×32×9 mm envelope of 6002 gives a D/d ratio of 2.13 and 8.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 6.2/2.84 kN load ratings, 0.2 kN fatigue load limit Cu NTN lists the grease limiting speed at 18000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 30 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6002LLB on the 15×32×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6002 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Order the C3 internal-clearance version (6002 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6002-RSR-NTN bearing?",
        "a": "A 6002-RSR-NTN deep-groove ball bearing has a 15 mm bore, 32 mm outer diameter and 9 mm width (0.591 × 1.26 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How should 6002-RSR-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 15 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6002-RSR-NTN need?",
        "a": "6002-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6002 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 6002?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6002LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 15×32×9 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6002LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6002-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6002-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6002-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6002",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6002-llb",
      "6002llb",
      "6002-RSR",
      "6002-rsr",
      "6002LLB",
      "6002-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6002-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6002ZZ",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 32,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 6.2,
    "static_load_kN": 2.84,
    "fatigue_load_limit_kN": 0.2,
    "limiting_speed_rpm": 18000,
    "max_rpm": 18000,
    "weight_g": 30,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6002-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 15 by five gives the 15 mm bore; the 32 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 15 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6002ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Interference on a 15 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6002 with C3 clearance and re-check the residual value after mounting.",
      "Choosing the 60xx extra-light section saves radial space at 15 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6215 before committing to the smaller envelope.",
      "Do not wash 6002-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6002-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6002-ZZ-NTN-C3. No clearance suffix means normal CN clearance.",
      "Measure the shaft, do not trust the drawing: a 15 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6002-ZZ-NTN.",
      "NTN catalogues the shielded version as 6002ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 15 mm bore the 6002 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6002 at 18000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6002 at 6.2 kN dynamic (C) and 2.84 kN static (C0), 0.2 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 30 g, 6002 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×32×9 mm envelope of 6002 gives a D/d ratio of 2.13 and 8.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 6.2/2.84 kN load ratings, 0.2 kN fatigue load limit Cu NTN lists the grease limiting speed at 18000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 30 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6002ZZ on the 15×32×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6002 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6002-ZZ-NTN bearing?",
        "a": "A 6002-ZZ-NTN deep-groove ball bearing has a 15 mm bore, 32 mm outer diameter and 9 mm width (0.591 × 1.26 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 6002-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 6000 compare with other series at the same 15 mm bore?",
        "a": "The second digit is the diameter series: 60 is the smallest standard section (32×9 mm, 8.5 mm radial section) at 15 mm bore — below 62/63/64 in load capacity, for light loads in compact spaces."
      },
      {
        "q": "What is the NTN suffix for a sealed 6002?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6002ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 15×32×9 mm ISO 15 envelope."
      },
      {
        "q": "Is 6002ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6002-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6002-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6002-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6002-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6002",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×32×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6002-zz",
      "6002zz",
      "6002-ZZ",
      "6002ZZ",
      "6002-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6202-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6202",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 35,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 8.6,
    "static_load_kN": 3.6,
    "fatigue_load_limit_kN": 0.28,
    "limiting_speed_rpm": 19000,
    "max_rpm": 19000,
    "weight_g": 45,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6202 carries bore code 15 = 15 mm. Outside diameter 35 mm and width 11 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 15 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "At 15 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6202 against the shaft shoulder while it cools so the ring cannot creep back.",
      "At 15 mm bore the 62xx light series is the workhorse section; its 35×11 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "The open 6202-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 15×35×11 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6202-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Do not quieten a noisy bearing by preloading it: the 6200-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "Vibration during standstill brinells the raceways of a 15 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "The open 6202 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 15 mm bore the 6202 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6202 at 19000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 6202 at 8.6 kN dynamic (C) and 3.6 kN static (C0), 0.28 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 45 g, 6202 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×35×11 mm envelope of 6202 gives a D/d ratio of 2.33 and 10.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 8.6/3.6 kN load ratings, 0.28 kN fatigue load limit Cu NTN lists the grease limiting speed at 19000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 45 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6202 on the 15×35×11 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6202 in a rated drive.",
      "Order the C3 internal-clearance version (6202 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6202-NTN bearing?",
        "a": "A 6202-NTN deep-groove ball bearing has a 15 mm bore, 35 mm outer diameter and 11 mm width (0.591 × 1.378 × 0.433 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What internal clearance does 6202-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6202-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6202 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6202-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 15 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN order number for an open 6202?",
        "a": "NTN lists the open 6202 under the bare designation 6202; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 15 mm bore envelope."
      },
      {
        "q": "Is 6202 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6202-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6202-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6202-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6202",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6202",
      "6202-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6202-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6202LLU",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 35,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 8.6,
    "static_load_kN": 3.6,
    "fatigue_load_limit_kN": 0.28,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "weight_g": 45,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6202 carries bore code 15 = 15 mm. Outside diameter 35 mm and width 11 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 15 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6202LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 15 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6202 with C3 for those conditions.",
      "The 62xx light series is the default general-purpose section at 15 mm bore; before upgrading to a 6315 for extra capacity, confirm the housing accepts a 35 mm OD and 11 mm width — it is not a drop-in swap.",
      "Contact seals add drag and heat: 6202-2RS-NTN runs slower and cooler-limited than the open 6202; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 6202-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 35 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6202-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6202LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 15 mm bore the 6202 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6202 at 15000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6202 at 8.6 kN dynamic (C) and 3.6 kN static (C0), 0.28 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 45 g, 6202 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×35×11 mm envelope of 6202 gives a D/d ratio of 2.33 and 10.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 8.6/3.6 kN load ratings, 0.28 kN fatigue load limit Cu NTN lists the grease limiting speed at 15000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 45 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6202LLU on the 15×35×11 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6202 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Order the C3 internal-clearance version (6202 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6202-2RS-NTN bearing?",
        "a": "A 6202-2RS-NTN deep-groove ball bearing has a 15 mm bore, 35 mm outer diameter and 11 mm width (0.591 × 1.378 × 0.433 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What does the 2RS suffix on 6202-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "How does the 6200 compare with other series at the same 15 mm bore?",
        "a": "The '2' is the light diameter series: 35×11 mm with a 10.0 mm radial section at 15 mm bore. A 6315 on the same bore is larger and higher-rated; a 6015 is smaller and lower-rated."
      },
      {
        "q": "What is the NTN suffix for a sealed 6202?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6202LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 15×35×11 mm ISO 15 envelope."
      },
      {
        "q": "Is 6202LLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6202-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6202-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6202-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6202",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6202-llu",
      "6202llu",
      "6202-2RS",
      "6202-2rs",
      "6202LLU",
      "6202-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6202-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6202LLB",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 35,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 8.6,
    "static_load_kN": 3.6,
    "fatigue_load_limit_kN": 0.28,
    "limiting_speed_rpm": 18000,
    "max_rpm": 18000,
    "weight_g": 45,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6202-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 15 by five gives the 15 mm bore; the 35 mm outside diameter and 11 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 15 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6202LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "At 15 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6202 against the shaft shoulder while it cools so the ring cannot creep back.",
      "At 15 mm bore the 62xx light series is the workhorse section; its 35×11 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "The low-drag lip of 6202-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 6202-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 15 mm bore position before relying on it as sealed-for-life.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 11 mm-wide ring of 6202-RSR-NTN drags the lip and overheats it.",
      "Measure the shaft, do not trust the drawing: a 15 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6202-RSR-NTN.",
      "NTN catalogues this low-friction non-contact seal as 6202LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 15 mm bore the 6202 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6202 at 18000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6202 at 8.6 kN dynamic (C) and 3.6 kN static (C0), 0.28 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 45 g, 6202 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×35×11 mm envelope of 6202 gives a D/d ratio of 2.33 and 10.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 8.6/3.6 kN load ratings, 0.28 kN fatigue load limit Cu NTN lists the grease limiting speed at 18000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 45 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6202LLB on the 15×35×11 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6202 in a rated drive.",
      "Order the C3 internal-clearance version (6202 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Standard catalogue stock of 6202 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6202-RSR-NTN bearing?",
        "a": "A 6202-RSR-NTN deep-groove ball bearing has a 15 mm bore, 35 mm outer diameter and 11 mm width (0.591 × 1.378 × 0.433 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6200 compare with other series at the same 15 mm bore?",
        "a": "The '2' is the light diameter series: 35×11 mm with a 10.0 mm radial section at 15 mm bore. A 6315 on the same bore is larger and higher-rated; a 6015 is smaller and lower-rated."
      },
      {
        "q": "Are 6202 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6202 uses the same ISO 15 envelope (15×35×11 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6202?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6202LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 15×35×11 mm ISO 15 envelope."
      },
      {
        "q": "Is 6202LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6202-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6202-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6202-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6202",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6202-llb",
      "6202llb",
      "6202-RSR",
      "6202-rsr",
      "6202LLB",
      "6202-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6202-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6202ZZ",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 35,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 8.6,
    "static_load_kN": 3.6,
    "fatigue_load_limit_kN": 0.28,
    "limiting_speed_rpm": 18000,
    "max_rpm": 18000,
    "weight_g": 45,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6202 carries bore code 15 = 15 mm. Outside diameter 35 mm and width 11 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 15 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6202ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "At 15 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6202 against the shaft shoulder while it cools so the ring cannot creep back.",
      "At 15 mm bore the 62xx light series is the workhorse section; its 35×11 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "Do not wash 6202-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6202-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 35 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6202-ZZ-NTN.",
      "Shaft and housing fillets must clear the bearing chamfer so the 11 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues the shielded version as 6202ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 15 mm bore the 6202 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6202 at 18000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6202 at 8.6 kN dynamic (C) and 3.6 kN static (C0), 0.28 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 45 g, 6202 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 15×35×11 mm envelope of 6202 gives a D/d ratio of 2.33 and 10.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 8.6/3.6 kN load ratings, 0.28 kN fatigue load limit Cu NTN lists the grease limiting speed at 18000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 45 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6202ZZ on the 15×35×11 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6202 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Order the C3 internal-clearance version (6202 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6202-ZZ-NTN bearing?",
        "a": "A 6202-ZZ-NTN deep-groove ball bearing has a 15 mm bore, 35 mm outer diameter and 11 mm width (0.591 × 1.378 × 0.433 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 6200 compare with other series at the same 15 mm bore?",
        "a": "The '2' is the light diameter series: 35×11 mm with a 10.0 mm radial section at 15 mm bore. A 6315 on the same bore is larger and higher-rated; a 6015 is smaller and lower-rated."
      },
      {
        "q": "Are 6202 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6202 uses the same ISO 15 envelope (15×35×11 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6202?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6202ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 15×35×11 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6202ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6202-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6202-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6202-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6202-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6202",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×35×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6202-zz",
      "6202zz",
      "6202-ZZ",
      "6202ZZ",
      "6202-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6302-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6302",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 42,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 12.7,
    "static_load_kN": 5.45,
    "fatigue_load_limit_kN": 0.42,
    "limiting_speed_rpm": 17000,
    "max_rpm": 17000,
    "weight_g": 82,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6302 carries bore code 15 = 15 mm. Outside diameter 42 mm and width 13 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 15 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "conveyor drives",
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "At 15 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6302 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 63xx medium series gains rating at 15 mm bore through a 42 mm OD and 13 mm width; the heavier rolling elements also trade away some speed versus a 6215.",
      "Storage matters for open bearings: 6302-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 6300-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6302 units.",
      "Never mix components between two 6302-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6300-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "The open 6302 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 15 mm bore the 6302 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6302 at 17000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 6302 at 12.7 kN dynamic (C) and 5.45 kN static (C0), 0.42 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 82 g, 6302 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 15×42×13 mm envelope of 6302 gives a D/d ratio of 2.80 and 13.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 12.7/5.45 kN load ratings, 0.42 kN fatigue load limit Cu NTN lists the grease limiting speed at 17000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 82 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6302 on the 15×42×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6302 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6302-NTN bearing?",
        "a": "A 6302-NTN deep-groove ball bearing has a 15 mm bore, 42 mm outer diameter and 13 mm width (0.591 × 1.654 × 0.512 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What does no suffix on 6302 mean?",
        "a": "A bare 6302 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "How does the 6300 compare with other series at the same 15 mm bore?",
        "a": "The '3' is the medium diameter series: 42×13 mm, 13.5 mm radial section at 15 mm bore, carrying more load than a 6215 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "What is the NTN order number for an open 6302?",
        "a": "NTN lists the open 6302 under the bare designation 6302; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 15 mm bore envelope."
      },
      {
        "q": "Is 6302 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6302-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6302-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6302-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6302",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6302",
      "6302-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6302-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6302LLU",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 42,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 12.7,
    "static_load_kN": 5.45,
    "fatigue_load_limit_kN": 0.42,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 82,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6302-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 15 by five gives the 15 mm bore; the 42 mm outside diameter and 13 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 15 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6302LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At 15 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6302 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 63xx medium series gains rating at 15 mm bore through a 42 mm OD and 13 mm width; the heavier rolling elements also trade away some speed versus a 6215.",
      "Contact seals add drag and heat: 6302-2RS-NTN runs slower and cooler-limited than the open 6302; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 6302-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Shaft and housing fillets must clear the bearing chamfer so the 13 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 42 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6302-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6302LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 15 mm bore the 6302 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6302 at 12000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6302 at 12.7 kN dynamic (C) and 5.45 kN static (C0), 0.42 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 82 g, 6302 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 15×42×13 mm envelope of 6302 gives a D/d ratio of 2.80 and 13.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 12.7/5.45 kN load ratings, 0.42 kN fatigue load limit Cu NTN lists the grease limiting speed at 12000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 82 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6302LLU on the 15×42×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6302 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6302 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6302-2RS-NTN bearing?",
        "a": "A 6302-2RS-NTN deep-groove ball bearing has a 15 mm bore, 42 mm outer diameter and 13 mm width (0.591 × 1.654 × 0.512 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 6300 compare with other series at the same 15 mm bore?",
        "a": "The '3' is the medium diameter series: 42×13 mm, 13.5 mm radial section at 15 mm bore, carrying more load than a 6215 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "Are 6302 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6302 uses the same ISO 15 envelope (15×42×13 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6302?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6302LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 15×42×13 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6302 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6302LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6302-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6302-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6302-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6302",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6302-llu",
      "6302llu",
      "6302-2RS",
      "6302-2rs",
      "6302LLU",
      "6302-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6302-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6302LLB",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 42,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 12.7,
    "static_load_kN": 5.45,
    "fatigue_load_limit_kN": 0.42,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "weight_g": 82,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6302 carries bore code 15 = 15 mm. Outside diameter 42 mm and width 13 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 15 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6302LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Interference on a 15 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6302 with C3 clearance and re-check the residual value after mounting.",
      "The 63xx medium section at 15 mm bore gains dynamic rating through larger rolling elements on a 42 mm OD; the penalty is mass and a lower limiting speed than the 6215 — do not specify it for speed-critical shafts.",
      "RSR low-friction seals on 6302-RSR-NTN run faster than contact-seal 6302-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6302-2RS instead.",
      "The low-drag lip of 6302-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The housing bore for the 42 mm OD should be round within IT7; an oval bore pinches the outer ring of 6302-RSR-NTN and shows up later as two-point loaded raceway wear.",
      "Never mix components between two 6302-RSR-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues this low-friction non-contact seal as 6302LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 15 mm bore the 6302 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6302 at 15000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6302 at 12.7 kN dynamic (C) and 5.45 kN static (C0), 0.42 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 82 g, 6302 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 15×42×13 mm envelope of 6302 gives a D/d ratio of 2.80 and 13.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 12.7/5.45 kN load ratings, 0.42 kN fatigue load limit Cu NTN lists the grease limiting speed at 15000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 82 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6302LLB on the 15×42×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6302 in a rated drive.",
      "Order the C3 internal-clearance version (6302 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6302-RSR-NTN bearing?",
        "a": "A 6302-RSR-NTN deep-groove ball bearing has a 15 mm bore, 42 mm outer diameter and 13 mm width (0.591 × 1.654 × 0.512 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What does the RSR suffix on 6302-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "How does the 6300 compare with other series at the same 15 mm bore?",
        "a": "The '3' is the medium diameter series: 42×13 mm, 13.5 mm radial section at 15 mm bore, carrying more load than a 6215 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "What is the NTN suffix for a sealed 6302?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6302LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 15×42×13 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6302LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6302-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6302-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6302-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6302",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6302-llb",
      "6302llb",
      "6302-RSR",
      "6302-rsr",
      "6302LLB",
      "6302-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6302-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6302ZZ",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 15,
    "D_mm": 42,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 12.7,
    "static_load_kN": 5.45,
    "fatigue_load_limit_kN": 0.42,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "weight_g": 82,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6302-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 15 by five gives the 15 mm bore; the 42 mm outside diameter and 13 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 15 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6302ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "conveyor drives",
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 15 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6302 with C3 for those conditions.",
      "The 63xx medium series gains rating at 15 mm bore through a 42 mm OD and 13 mm width; the heavier rolling elements also trade away some speed versus a 6215.",
      "Do not wash 6302-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6302-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 42 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6302-ZZ-NTN.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6302-ZZ-NTN-C3. No clearance suffix means normal CN clearance.",
      "NTN catalogues the shielded version as 6302ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 15 mm bore the 6302 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6302 at 15000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6302 at 12.7 kN dynamic (C) and 5.45 kN static (C0), 0.42 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 82 g, 6302 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 15×42×13 mm envelope of 6302 gives a D/d ratio of 2.80 and 13.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 12.7/5.45 kN load ratings, 0.42 kN fatigue load limit Cu NTN lists the grease limiting speed at 15000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 82 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6302ZZ on the 15×42×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6302 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6302 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6302-ZZ-NTN bearing?",
        "a": "A 6302-ZZ-NTN deep-groove ball bearing has a 15 mm bore, 42 mm outer diameter and 13 mm width (0.591 × 1.654 × 0.512 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 6302-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 6300 compare with other series at the same 15 mm bore?",
        "a": "The '3' is the medium diameter series: 42×13 mm, 13.5 mm radial section at 15 mm bore, carrying more load than a 6215 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "What is the NTN suffix for a sealed 6302?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6302ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 15×42×13 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6302 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6302ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6302-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6302-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6302-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6302-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6302",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 15×42×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6302-zz",
      "6302zz",
      "6302-ZZ",
      "6302ZZ",
      "6302-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61803-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6803",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 26,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.47,
    "static_load_kN": 1.46,
    "fatigue_load_limit_kN": 0.1,
    "limiting_speed_rpm": 24000,
    "max_rpm": 24000,
    "weight_g": 8,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61803 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 17 by five gives the 17 mm bore; the 26 mm outside diameter and 5 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 17 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At 17 mm bore the ring mass is significant: heat 61803 on an induction heater (max 120 °C), never over an open flame, and plan puller access or a withdrawal sleeve now for the day it has to come off again.",
      "Only 4.5 mm of radial section separates bore and OD on the 618xx series at 17 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6217.",
      "The open 61803-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 17×26×5 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 61800-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61803 units.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61800-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "The housing bore for the 26 mm OD should be round within IT7; an oval bore pinches the outer ring of 61803-NTN and shows up later as two-point loaded raceway wear.",
      "The open 61803 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 17 mm bore the 61803 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61803 at 24000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "At 2.47 kN dynamic load rating (C) and 1.46 kN static (C0), 0.1 kN fatigue load limit Cu, 61803 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 8 g, 61803 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 17×26×5 mm envelope of 61803 gives a D/d ratio of 1.53 and 4.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 2.47/1.46 kN load ratings, 0.1 kN fatigue load limit Cu NTN lists the grease limiting speed at 24000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 8 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6803 on the 17×26×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61803 in a rated drive.",
      "Order the C3 internal-clearance version (61803 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61803 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61803-NTN bearing?",
        "a": "A 61803-NTN deep-groove ball bearing has a 17 mm bore, 26 mm outer diameter and 5 mm width (0.669 × 1.024 × 0.197 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What does no suffix on 61803 mean?",
        "a": "A bare 61803 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "How does the 61800 compare with other series at the same 17 mm bore?",
        "a": "618 is an extra-thin section: 26×5 mm, only 4.5 mm radial section at 17 mm bore, far smaller than a 6217, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "What is the NTN order number for an open 61803?",
        "a": "NTN lists the open 61803 under the bare designation 6803; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 17 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6803?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61803-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61803-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61803-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6803",
      "61803",
      "61803-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61803-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6803LLU",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 26,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.47,
    "static_load_kN": 1.46,
    "fatigue_load_limit_kN": 0.1,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "weight_g": 8,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61803-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 17 by five gives the 17 mm bore; the 26 mm outside diameter and 5 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 17 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6803LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "At 17 mm bore the ring mass is significant: heat 61803 on an induction heater (max 120 °C), never over an open flame, and plan puller access or a withdrawal sleeve now for the day it has to come off again.",
      "Only 4.5 mm of radial section separates bore and OD on the 618xx series at 17 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6217.",
      "Heat is the enemy of the sealed 61803-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 61803-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Shaft and housing fillets must clear the bearing chamfer so the 5 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 5 mm-wide ring of 61803-2RS-NTN drags the lip and overheats it.",
      "NTN catalogues the contact-sealed version as 6803LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 17 mm bore the 61803 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61803 at 15000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 2.47 kN dynamic load rating (C) and 1.46 kN static (C0), 0.1 kN fatigue load limit Cu, 61803 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 8 g, 61803 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 17×26×5 mm envelope of 61803 gives a D/d ratio of 1.53 and 4.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 2.47/1.46 kN load ratings, 0.1 kN fatigue load limit Cu NTN lists the grease limiting speed at 15000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 8 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6803LLU on the 17×26×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61803 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Standard catalogue stock of 61803 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61803-2RS-NTN bearing?",
        "a": "A 61803-2RS-NTN deep-groove ball bearing has a 17 mm bore, 26 mm outer diameter and 5 mm width (0.669 × 1.024 × 0.197 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 61800 compare with other series at the same 17 mm bore?",
        "a": "618 is an extra-thin section: 26×5 mm, only 4.5 mm radial section at 17 mm bore, far smaller than a 6217, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "Are 61803 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61803 uses the same ISO 15 envelope (17×26×5 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61803?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6803LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 17×26×5 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61803 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6803LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61803-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61803-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61803-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61803-llu",
      "6803llu",
      "61803-2RS",
      "61803-2rs",
      "6803LLU",
      "61803-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61803-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6803LLB",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 26,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.47,
    "static_load_kN": 1.46,
    "fatigue_load_limit_kN": 0.1,
    "limiting_speed_rpm": 24000,
    "max_rpm": 24000,
    "weight_g": 8,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61803-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 17 by five gives the 17 mm bore; the 26 mm outside diameter and 5 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 17 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6803LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Mount this 17 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.",
      "The 618xx thin section at 17 mm bore has only a 4.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6217.",
      "The low-drag lip of 61803-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 61803-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 17 mm bore position before relying on it as sealed-for-life.",
      "Never mix components between two 61803-RSR-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Vibration during standstill brinells the raceways of a 17 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues this low-friction non-contact seal as 6803LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 17 mm bore the 61803 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61803 at 24000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 2.47 kN dynamic load rating (C) and 1.46 kN static (C0), 0.1 kN fatigue load limit Cu, 61803 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 8 g, 61803 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 17×26×5 mm envelope of 61803 gives a D/d ratio of 1.53 and 4.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 2.47/1.46 kN load ratings, 0.1 kN fatigue load limit Cu NTN lists the grease limiting speed at 24000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 8 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6803LLB on the 17×26×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61803 in a rated drive.",
      "Order the C3 internal-clearance version (61803 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61803-RSR-NTN bearing?",
        "a": "A 61803-RSR-NTN deep-groove ball bearing has a 17 mm bore, 26 mm outer diameter and 5 mm width (0.669 × 1.024 × 0.197 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What does the RSR suffix on 61803-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "How does the 61800 compare with other series at the same 17 mm bore?",
        "a": "618 is an extra-thin section: 26×5 mm, only 4.5 mm radial section at 17 mm bore, far smaller than a 6217, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "What is the NTN suffix for a sealed 61803?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6803LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 17×26×5 mm ISO 15 envelope."
      },
      {
        "q": "Is 6803LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61803-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61803-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61803-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61803-llb",
      "6803llb",
      "61803-RSR",
      "61803-rsr",
      "6803LLB",
      "61803-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61803-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6803ZZ",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 26,
    "B_mm": 5,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 2.47,
    "static_load_kN": 1.46,
    "fatigue_load_limit_kN": 0.1,
    "limiting_speed_rpm": 24000,
    "max_rpm": 24000,
    "weight_g": 8,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61803-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 17 by five gives the 17 mm bore; the 26 mm outside diameter and 5 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 17 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6803ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At 17 mm bore the ring mass is significant: heat 61803 on an induction heater (max 120 °C), never over an open flame, and plan puller access or a withdrawal sleeve now for the day it has to come off again.",
      "The 618xx thin section at 17 mm bore has only a 4.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6217.",
      "ZZ shields are non-contact: 61803-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61803-2RS for that.",
      "Do not wash 61803-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 26 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61803-ZZ-NTN.",
      "Never mix components between two 61803-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the shielded version as 6803ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 17 mm bore the 61803 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61803 at 24000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 2.47 kN dynamic load rating (C) and 1.46 kN static (C0), 0.1 kN fatigue load limit Cu, 61803 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 8 g, 61803 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 17×26×5 mm envelope of 61803 gives a D/d ratio of 1.53 and 4.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 2.47/1.46 kN load ratings, 0.1 kN fatigue load limit Cu NTN lists the grease limiting speed at 24000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 8 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6803ZZ on the 17×26×5 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61803 in a rated drive.",
      "Standard catalogue stock of 61803 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61803-ZZ-NTN bearing?",
        "a": "A 61803-ZZ-NTN deep-groove ball bearing has a 17 mm bore, 26 mm outer diameter and 5 mm width (0.669 × 1.024 × 0.197 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How should 61803-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 17 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 61803-ZZ-NTN need?",
        "a": "61803-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "What is the NTN suffix for a sealed 61803?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6803ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 17×26×5 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61803 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6803ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61803-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61803-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61803-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61803-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×26×5 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61803-zz",
      "6803zz",
      "61803-ZZ",
      "6803ZZ",
      "61803-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61903-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6903JRX",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 30,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.15,
    "static_load_kN": 2.58,
    "fatigue_load_limit_kN": 0.2,
    "limiting_speed_rpm": 22000,
    "max_rpm": 22000,
    "weight_g": 18,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61903 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 17 by five gives the 17 mm bore; the 30 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 17 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Mount this 17 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.",
      "The 619xx thin section at 17 mm bore (6.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "Storage matters for open bearings: 61903-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 61900-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61903 units.",
      "The housing bore for the 30 mm OD should be round within IT7; an oval bore pinches the outer ring of 61903-NTN and shows up later as two-point loaded raceway wear.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "The open 61903 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 17 mm bore the 61903 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61903 at 22000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 61903 at 5.15 kN dynamic (C) and 2.58 kN static (C0), 0.2 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 18 g, 61903 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 17×30×7 mm envelope of 61903 gives a D/d ratio of 1.76 and 6.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 5.15/2.58 kN load ratings, 0.2 kN fatigue load limit Cu NTN lists the grease limiting speed at 22000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 18 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6903JRX on the 17×30×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61903 in a rated drive.",
      "Order the C3 internal-clearance version (61903 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61903 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61903-NTN bearing?",
        "a": "A 61903-NTN deep-groove ball bearing has a 17 mm bore, 30 mm outer diameter and 7 mm width (0.669 × 1.181 × 0.276 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What internal clearance does 61903-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61903-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61903 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61903-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 17 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN order number for an open 61903?",
        "a": "NTN lists the open 61903 under the bare designation 6903JRX; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 17 mm bore envelope."
      },
      {
        "q": "Is 6903JRX a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61903-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61903-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61903-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61903",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6903jrx",
      "61903",
      "6903JRX",
      "61903-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61903-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6903JRXLLU",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 30,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.15,
    "static_load_kN": 2.58,
    "fatigue_load_limit_kN": 0.2,
    "limiting_speed_rpm": 14000,
    "max_rpm": 14000,
    "weight_g": 18,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61903-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 17 by five gives the 17 mm bore; the 30 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 17 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6903JRXLLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Mount this 17 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.",
      "The 619xx thin section at 17 mm bore (6.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "Contact seals add drag and heat: 61903-2RS-NTN runs slower and cooler-limited than the open 61903; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 61903-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Shaft and housing fillets must clear the bearing chamfer so the 7 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 30 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61903-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6903JRXLLU (suffix RXLLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 17 mm bore the 61903 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61903 at 14000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 61903 at 5.15 kN dynamic (C) and 2.58 kN static (C0), 0.2 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 18 g, 61903 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 17×30×7 mm envelope of 61903 gives a D/d ratio of 1.76 and 6.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 5.15/2.58 kN load ratings, 0.2 kN fatigue load limit Cu NTN lists the grease limiting speed at 14000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 18 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6903JRXLLU on the 17×30×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61903 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Order the C3 internal-clearance version (61903 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61903-2RS-NTN bearing?",
        "a": "A 61903-2RS-NTN deep-groove ball bearing has a 17 mm bore, 30 mm outer diameter and 7 mm width (0.669 × 1.181 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How should 61903-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 17 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 61903-2RS-NTN need?",
        "a": "61903-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61903 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 61903?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6903JRXLLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 17×30×7 mm ISO 15 envelope."
      },
      {
        "q": "Is 6903JRXLLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61903-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61903-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61903-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61903",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61903-llu",
      "6903jrxllu",
      "6903llu",
      "61903-2RS",
      "61903-2rs",
      "6903JRXLLU",
      "61903-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61903-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6903JRXLLB",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 30,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.15,
    "static_load_kN": 2.58,
    "fatigue_load_limit_kN": 0.2,
    "limiting_speed_rpm": 22000,
    "max_rpm": 22000,
    "weight_g": 18,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61903-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 17 by five gives the 17 mm bore; the 30 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 17 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6903JRXLLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At 17 mm bore the ring mass is significant: heat 61903 on an induction heater (max 120 °C), never over an open flame, and plan puller access or a withdrawal sleeve now for the day it has to come off again.",
      "The 619xx thin section at 17 mm bore (6.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "RSR low-friction seals on 61903-RSR-NTN run faster than contact-seal 61903-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61903-2RS instead.",
      "The low-drag lip of 61903-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 7 mm-wide ring of 61903-RSR-NTN drags the lip and overheats it.",
      "A 17 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues this low-friction non-contact seal as 6903JRXLLB (suffix RXLLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 17 mm bore the 61903 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61903 at 22000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 61903 at 5.15 kN dynamic (C) and 2.58 kN static (C0), 0.2 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 18 g, 61903 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 17×30×7 mm envelope of 61903 gives a D/d ratio of 1.76 and 6.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 5.15/2.58 kN load ratings, 0.2 kN fatigue load limit Cu NTN lists the grease limiting speed at 22000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 18 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6903JRXLLB on the 17×30×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61903 in a rated drive.",
      "Order the C3 internal-clearance version (61903 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Standard catalogue stock of 61903 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61903-RSR-NTN bearing?",
        "a": "A 61903-RSR-NTN deep-groove ball bearing has a 17 mm bore, 30 mm outer diameter and 7 mm width (0.669 × 1.181 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "Are 61903 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61903 uses the same ISO 15 envelope (17×30×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 61903-RSR-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61903-RSR-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61903 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 61903?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6903JRXLLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 17×30×7 mm ISO 15 envelope."
      },
      {
        "q": "Is 6903JRXLLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61903-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61903-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61903-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61903",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61903-llb",
      "6903jrxllb",
      "6903llb",
      "61903-RSR",
      "61903-rsr",
      "6903JRXLLB",
      "61903-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61903-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6903JRXZZ",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 30,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.15,
    "static_load_kN": 2.58,
    "fatigue_load_limit_kN": 0.2,
    "limiting_speed_rpm": 22000,
    "max_rpm": 22000,
    "weight_g": 18,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61903 carries bore code 17 = 17 mm. Outside diameter 30 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 17 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6903JRXZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Large bores like the 17 mm of 61903-ZZ-NTN demand clean, burr-free seats; one raised burr under a ring this size cocks the bearing and concentrates load at the raceway edge, cutting life drastically.",
      "The 619xx thin section (6.5 mm section height at 17 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "Do not wash 61903-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 61903-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61903-ZZ-NTN-C3. No clearance suffix means normal CN clearance.",
      "Measure the shaft, do not trust the drawing: a 17 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61903-ZZ-NTN.",
      "NTN catalogues the shielded version as 6903JRXZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 17 mm bore the 61903 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 61903 at 22000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 61903 at 5.15 kN dynamic (C) and 2.58 kN static (C0), 0.2 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 18 g, 61903 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 17×30×7 mm envelope of 61903 gives a D/d ratio of 1.76 and 6.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 5.15/2.58 kN load ratings, 0.2 kN fatigue load limit Cu NTN lists the grease limiting speed at 22000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 18 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6903JRXZZ on the 17×30×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61903 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61903-ZZ-NTN bearing?",
        "a": "A 61903-ZZ-NTN deep-groove ball bearing has a 17 mm bore, 30 mm outer diameter and 7 mm width (0.669 × 1.181 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How should 61903-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 17 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 61903-ZZ-NTN need?",
        "a": "61903-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "What is the NTN suffix for a sealed 61903?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6903JRXZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 17×30×7 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6903JRXZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61903-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61903-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61903-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61903-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61903",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×30×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61903-zz",
      "6903jrxzz",
      "6903zz",
      "61903-ZZ",
      "6903JRXZZ",
      "61903-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "16003-NTN",
    "brand": "NTN",
    "manufacturer_designation": "16003",
    "series": "16000-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 35,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 7.55,
    "static_load_kN": 3.35,
    "fatigue_load_limit_kN": 0.26,
    "limiting_speed_rpm": 20000,
    "max_rpm": 20000,
    "weight_g": 32,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "16003 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the narrow 160xx section of the ISO 15 general plan, multiplying bore code 17 by five gives the 17 mm bore; the 35 mm outside diameter and 8 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 17 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "large gearboxes",
      "industrial fans and blowers",
      "hoists and winches",
      "heavy conveyors"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Mount this 17 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.",
      "Because the 160xx narrow section shares the 35 mm OD of the 6017 at 17 mm bore but is only 8 mm wide, a housing machined for the wider bearing needs a spacer or relocated circlip — never assume width interchangeability.",
      "Storage matters for open bearings: 16003-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 16000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 16003 units.",
      "Shaft and housing fillets must clear the bearing chamfer so the 8 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Measure the shaft, do not trust the drawing: a 17 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 16003-NTN.",
      "The open 16003 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 17 mm bore the 16003 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 16003 at 20000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 16003 at 7.55 kN dynamic (C) and 3.35 kN static (C0), 0.26 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 32 g, 16003 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 17×35×8 mm envelope of 16003 gives a D/d ratio of 2.06 and 9.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 7.55/3.35 kN load ratings, 0.26 kN fatigue load limit Cu NTN lists the grease limiting speed at 20000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 32 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 16003 on the 17×35×8 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 16003 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 16003 is listed.",
      "Order the C3 internal-clearance version (16003 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 16003-NTN bearing?",
        "a": "A 16003-NTN deep-groove ball bearing has a 17 mm bore, 35 mm outer diameter and 8 mm width (0.669 × 1.378 × 0.315 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 16003 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 16003 uses the same ISO 15 envelope (17×35×8 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 16003-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 16003-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 16003 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 16003?",
        "a": "NTN lists the open 16003 under the bare designation 16003; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 17 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 16003?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "16003",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×35×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "16003-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×35×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "16003",
      "16003-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6203-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6203",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 40,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.6,
    "static_load_kN": 4.6,
    "fatigue_load_limit_kN": 0.35,
    "limiting_speed_rpm": 18000,
    "max_rpm": 18000,
    "weight_g": 66,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6203 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 17 by five gives the 17 mm bore; the 40 mm outside diameter and 12 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 17 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "industrial fans and blowers",
      "hoists and winches",
      "heavy conveyors",
      "pulp and paper machinery"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Large bores like the 17 mm of 6203-NTN demand clean, burr-free seats; one raised burr under a ring this size cocks the bearing and concentrates load at the raceway edge, cutting life drastically.",
      "At 17 mm bore the 62xx light series is the workhorse section; its 40×12 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "The open 6203-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 17×40×12 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6203-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Measure the shaft, do not trust the drawing: a 17 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6203-NTN.",
      "The open 6203 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 17 mm bore the 6203 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6203 at 18000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 6203 at 10.6 kN dynamic (C) and 4.6 kN static (C0), 0.35 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 66 g, 6203 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 17×40×12 mm envelope of 6203 gives a D/d ratio of 2.35 and 11.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 10.6/4.6 kN load ratings, 0.35 kN fatigue load limit Cu NTN lists the grease limiting speed at 18000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 66 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6203 on the 17×40×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6203 in a rated drive.",
      "Standard catalogue stock of 6203 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Order the C3 internal-clearance version (6203 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6203-NTN bearing?",
        "a": "A 6203-NTN deep-groove ball bearing has a 17 mm bore, 40 mm outer diameter and 12 mm width (0.669 × 1.575 × 0.472 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6200 compare with other series at the same 17 mm bore?",
        "a": "The '2' is the light diameter series: 40×12 mm with an 11.5 mm radial section at 17 mm bore. A 6317 on the same bore is larger and higher-rated; a 6017 is smaller and lower-rated."
      },
      {
        "q": "Are 6203 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6203 uses the same ISO 15 envelope (17×40×12 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 6203?",
        "a": "NTN lists the open 6203 under the bare designation 6203; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 17 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6203?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6203-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6203-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6203-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6203",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6203",
      "6203-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6203-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6203LLU",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 40,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.6,
    "static_load_kN": 4.6,
    "fatigue_load_limit_kN": 0.35,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 66,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6203 carries bore code 17 = 17 mm. Outside diameter 40 mm and width 12 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 17 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6203LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "hoists and winches",
      "heavy conveyors",
      "pulp and paper machinery",
      "medium and heavy industrial drives"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Large bores like the 17 mm of 6203-2RS-NTN demand clean, burr-free seats; one raised burr under a ring this size cocks the bearing and concentrates load at the raceway edge, cutting life drastically.",
      "At 17 mm bore the 62xx light series is the workhorse section; its 40×12 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "Heat is the enemy of the sealed 6203-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 6203-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Vibration during standstill brinells the raceways of a 17 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6203-2RS-NTN-C3. No clearance suffix means normal CN clearance.",
      "NTN catalogues the contact-sealed version as 6203LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 17 mm bore the 6203 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6203 at 12000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6203 at 10.6 kN dynamic (C) and 4.6 kN static (C0), 0.35 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 66 g, 6203 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 17×40×12 mm envelope of 6203 gives a D/d ratio of 2.35 and 11.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 10.6/4.6 kN load ratings, 0.35 kN fatigue load limit Cu NTN lists the grease limiting speed at 12000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 66 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6203LLU on the 17×40×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6203 in a rated drive.",
      "Order the C3 internal-clearance version (6203 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Standard catalogue stock of 6203 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6203-2RS-NTN bearing?",
        "a": "A 6203-2RS-NTN deep-groove ball bearing has a 17 mm bore, 40 mm outer diameter and 12 mm width (0.669 × 1.575 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 6203 bore code work?",
        "a": "The last two digits of 6203 are bore code 17, giving 17 × 5 = 17 mm bore. The 40 mm outside diameter and 12 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the 2RS suffix on 6203-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "What is the NTN suffix for a sealed 6203?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6203LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 17×40×12 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6203LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6203-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6203-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6203-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6203",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6203-llu",
      "6203llu",
      "6203-2RS",
      "6203-2rs",
      "6203LLU",
      "6203-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6203-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6203LLB",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 40,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.6,
    "static_load_kN": 4.6,
    "fatigue_load_limit_kN": 0.35,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "weight_g": 66,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6203 carries bore code 17 = 17 mm. Outside diameter 40 mm and width 12 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 17 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6203LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "large gearboxes",
      "industrial fans and blowers",
      "hoists and winches",
      "heavy conveyors"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "At 17 mm bore the ring mass is significant: heat 6203 on an induction heater (max 120 °C), never over an open flame, and plan puller access or a withdrawal sleeve now for the day it has to come off again.",
      "At 17 mm bore the 62xx light series is the workhorse section; its 40×12 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "RSR low-friction seals on 6203-RSR-NTN run faster than contact-seal 6203-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6203-2RS instead.",
      "The non-contact lip of 6203-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 17 mm bore position before relying on it as sealed-for-life.",
      "A 17 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6203-RSR-NTN-C3. No clearance suffix means normal CN clearance.",
      "NTN catalogues this low-friction non-contact seal as 6203LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 17 mm bore the 6203 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6203 at 15000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6203 at 10.6 kN dynamic (C) and 4.6 kN static (C0), 0.35 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 66 g, 6203 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 17×40×12 mm envelope of 6203 gives a D/d ratio of 2.35 and 11.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 10.6/4.6 kN load ratings, 0.35 kN fatigue load limit Cu NTN lists the grease limiting speed at 15000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 66 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6203LLB on the 17×40×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6203 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Standard catalogue stock of 6203 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6203-RSR-NTN bearing?",
        "a": "A 6203-RSR-NTN deep-groove ball bearing has a 17 mm bore, 40 mm outer diameter and 12 mm width (0.669 × 1.575 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What does the RSR suffix on 6203-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "How does the 6200 compare with other series at the same 17 mm bore?",
        "a": "The '2' is the light diameter series: 40×12 mm with an 11.5 mm radial section at 17 mm bore. A 6317 on the same bore is larger and higher-rated; a 6017 is smaller and lower-rated."
      },
      {
        "q": "What is the NTN suffix for a sealed 6203?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6203LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 17×40×12 mm ISO 15 envelope."
      },
      {
        "q": "Is 6203LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6203-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6203-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6203-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6203",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6203-llb",
      "6203llb",
      "6203-RSR",
      "6203-rsr",
      "6203LLB",
      "6203-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6203-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6203ZZ",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 40,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.6,
    "static_load_kN": 4.6,
    "fatigue_load_limit_kN": 0.35,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "weight_g": 66,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6203-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 17 by five gives the 17 mm bore; the 40 mm outside diameter and 12 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 17 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6203ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "large gearboxes",
      "industrial fans and blowers",
      "hoists and winches",
      "heavy conveyors"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "At 17 mm bore the ring mass is significant: heat 6203 on an induction heater (max 120 °C), never over an open flame, and plan puller access or a withdrawal sleeve now for the day it has to come off again.",
      "The 62xx light series is the default general-purpose section at 17 mm bore; before upgrading to a 6317 for extra capacity, confirm the housing accepts a 40 mm OD and 12 mm width — it is not a drop-in swap.",
      "ZZ shields are non-contact: 6203-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6203-2RS for that.",
      "Shielded 6203-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Do not quieten a noisy bearing by preloading it: the 6200-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues the shielded version as 6203ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 17 mm bore the 6203 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6203 at 15000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6203 at 10.6 kN dynamic (C) and 4.6 kN static (C0), 0.35 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 66 g, 6203 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 17×40×12 mm envelope of 6203 gives a D/d ratio of 2.35 and 11.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 10.6/4.6 kN load ratings, 0.35 kN fatigue load limit Cu NTN lists the grease limiting speed at 15000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 66 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6203ZZ on the 17×40×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6203 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6203-ZZ-NTN bearing?",
        "a": "A 6203-ZZ-NTN deep-groove ball bearing has a 17 mm bore, 40 mm outer diameter and 12 mm width (0.669 × 1.575 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "Are 6203 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6203 uses the same ISO 15 envelope (17×40×12 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 6203-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6203-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6203 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 6203?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6203ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 17×40×12 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6203 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6203ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6203-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6203-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6203-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6203-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6203",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×40×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6203-zz",
      "6203zz",
      "6203-ZZ",
      "6203ZZ",
      "6203-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6303-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6303",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 47,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 15,
    "static_load_kN": 6.55,
    "fatigue_load_limit_kN": 0.51,
    "limiting_speed_rpm": 16000,
    "max_rpm": 16000,
    "weight_g": 115,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6303 carries bore code 17 = 17 mm. Outside diameter 47 mm and width 14 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 17 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "heavy conveyors",
      "pulp and paper machinery",
      "medium and heavy industrial drives",
      "large gearboxes"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Mount this 17 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.",
      "The 63xx medium series gains rating at 17 mm bore through a 47 mm OD and 14 mm width; the heavier rolling elements also trade away some speed versus a 6217.",
      "The open 6303-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 17×47×14 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6303-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Do not quieten a noisy bearing by preloading it: the 6300-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "Measure the shaft, do not trust the drawing: a 17 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6303-NTN.",
      "The open 6303 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 17 mm bore the 6303 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6303 at 16000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "At 15 kN dynamic load rating (C) and 6.55 kN static (C0), 0.51 kN fatigue load limit Cu, 6303 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 115 g, 6303 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 17×47×14 mm envelope of 6303 gives a D/d ratio of 2.76 and 15.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 15/6.55 kN load ratings, 0.51 kN fatigue load limit Cu NTN lists the grease limiting speed at 16000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 115 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6303 on the 17×47×14 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6303 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6303 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6303-NTN bearing?",
        "a": "A 6303-NTN deep-groove ball bearing has a 17 mm bore, 47 mm outer diameter and 14 mm width (0.669 × 1.85 × 0.551 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How should 6303-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 17 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6303-NTN need?",
        "a": "The open 6303-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "What is the NTN order number for an open 6303?",
        "a": "NTN lists the open 6303 under the bare designation 6303; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 17 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6303 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6303 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6303-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-2RS",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6303-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6303-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6303",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6303",
      "6303-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6303-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6303LLU",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 47,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 15,
    "static_load_kN": 6.55,
    "fatigue_load_limit_kN": 0.51,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "weight_g": 115,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6303-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 17 by five gives the 17 mm bore; the 47 mm outside diameter and 14 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 17 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6303LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "heavy conveyors",
      "pulp and paper machinery",
      "medium and heavy industrial drives",
      "large gearboxes"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "At 17 mm bore the ring mass is significant: heat 6303 on an induction heater (max 120 °C), never over an open flame, and plan puller access or a withdrawal sleeve now for the day it has to come off again.",
      "The 63xx medium section at 17 mm bore gains dynamic rating through larger rolling elements on a 47 mm OD; the penalty is mass and a lower limiting speed than the 6217 — do not specify it for speed-critical shafts.",
      "Contact seals add drag and heat: 6303-2RS-NTN runs slower and cooler-limited than the open 6303; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 6303-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6303-2RS-NTN-C3. No clearance suffix means normal CN clearance.",
      "Never mix components between two 6303-2RS-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the contact-sealed version as 6303LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 17 mm bore the 6303 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "At 11000 r/min the grease limiting speed for 6303 covers most general-purpose industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "At 15 kN dynamic load rating (C) and 6.55 kN static (C0), 0.51 kN fatigue load limit Cu, 6303 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 115 g, 6303 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 17×47×14 mm envelope of 6303 gives a D/d ratio of 2.76 and 15.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 15/6.55 kN load ratings, 0.51 kN fatigue load limit Cu NTN lists the grease limiting speed at 11000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 115 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6303LLU on the 17×47×14 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6303 in a rated drive.",
      "Standard catalogue stock of 6303 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6303-2RS-NTN bearing?",
        "a": "A 6303-2RS-NTN deep-groove ball bearing has a 17 mm bore, 47 mm outer diameter and 14 mm width (0.669 × 1.85 × 0.551 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 6303 bore code work?",
        "a": "The last two digits of 6303 are bore code 17, giving 17 × 5 = 17 mm bore. The 47 mm outside diameter and 14 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the 2RS suffix on 6303-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "What is the NTN suffix for a sealed 6303?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6303LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 17×47×14 mm ISO 15 envelope."
      },
      {
        "q": "Is 6303LLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6303-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-2RS",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6303-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6303-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6303",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6303-llu",
      "6303llu",
      "6303-2RS",
      "6303-2rs",
      "6303LLU",
      "6303-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6303-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6303LLB",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 47,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 15,
    "static_load_kN": 6.55,
    "fatigue_load_limit_kN": 0.51,
    "limiting_speed_rpm": 14000,
    "max_rpm": 14000,
    "weight_g": 115,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6303 carries bore code 17 = 17 mm. Outside diameter 47 mm and width 14 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 17 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6303LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "heavy conveyors",
      "pulp and paper machinery",
      "medium and heavy industrial drives",
      "large gearboxes"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Mount this 17 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.",
      "The 63xx medium series gains rating at 17 mm bore through a 47 mm OD and 14 mm width; the heavier rolling elements also trade away some speed versus a 6217.",
      "RSR low-friction seals on 6303-RSR-NTN run faster than contact-seal 6303-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6303-2RS instead.",
      "The low-drag lip of 6303-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "Shaft and housing fillets must clear the bearing chamfer so the 14 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues this low-friction non-contact seal as 6303LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 17 mm bore the 6303 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6303 at 14000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 15 kN dynamic load rating (C) and 6.55 kN static (C0), 0.51 kN fatigue load limit Cu, 6303 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 115 g, 6303 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 17×47×14 mm envelope of 6303 gives a D/d ratio of 2.76 and 15.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 15/6.55 kN load ratings, 0.51 kN fatigue load limit Cu NTN lists the grease limiting speed at 14000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 115 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6303LLB on the 17×47×14 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6303 in a rated drive.",
      "Order the C3 internal-clearance version (6303 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6303 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6303-RSR-NTN bearing?",
        "a": "A 6303-RSR-NTN deep-groove ball bearing has a 17 mm bore, 47 mm outer diameter and 14 mm width (0.669 × 1.85 × 0.551 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6300 compare with other series at the same 17 mm bore?",
        "a": "The '3' is the medium diameter series: 47×14 mm, 15.0 mm radial section at 17 mm bore, carrying more load than a 6217 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "Are 6303 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6303 uses the same ISO 15 envelope (17×47×14 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6303?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6303LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 17×47×14 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6303LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6303-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-2RS",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6303-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6303-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6303",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6303-llb",
      "6303llb",
      "6303-RSR",
      "6303-rsr",
      "6303LLB",
      "6303-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6303-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6303ZZ",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 47,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 15,
    "static_load_kN": 6.55,
    "fatigue_load_limit_kN": 0.51,
    "limiting_speed_rpm": 14000,
    "max_rpm": 14000,
    "weight_g": 115,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6303 carries bore code 17 = 17 mm. Outside diameter 47 mm and width 14 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 17 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6303ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "hoists and winches",
      "heavy conveyors",
      "pulp and paper machinery",
      "medium and heavy industrial drives"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Mount this 17 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.",
      "The 63xx medium series gains rating at 17 mm bore through a 47 mm OD and 14 mm width; the heavier rolling elements also trade away some speed versus a 6217.",
      "ZZ shields are non-contact: 6303-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6303-2RS for that.",
      "Shielded 6303-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 14 mm-wide ring of 6303-ZZ-NTN drags the lip and overheats it.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues the shielded version as 6303ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 17 mm bore the 6303 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6303 at 14000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 15 kN dynamic load rating (C) and 6.55 kN static (C0), 0.51 kN fatigue load limit Cu, 6303 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 115 g, 6303 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 17×47×14 mm envelope of 6303 gives a D/d ratio of 2.76 and 15.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 15/6.55 kN load ratings, 0.51 kN fatigue load limit Cu NTN lists the grease limiting speed at 14000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 115 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6303ZZ on the 17×47×14 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6303 in a rated drive.",
      "Order the C3 internal-clearance version (6303 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6303-ZZ-NTN bearing?",
        "a": "A 6303-ZZ-NTN deep-groove ball bearing has a 17 mm bore, 47 mm outer diameter and 14 mm width (0.669 × 1.85 × 0.551 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 6303-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 6300 compare with other series at the same 17 mm bore?",
        "a": "The '3' is the medium diameter series: 47×14 mm, 15.0 mm radial section at 17 mm bore, carrying more load than a 6217 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "What is the NTN suffix for a sealed 6303?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6303ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 17×47×14 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6303 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6303ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6303-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-2RS",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6303-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6303-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6303-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6303",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6303-zz",
      "6303zz",
      "6303-ZZ",
      "6303ZZ",
      "6303-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6403-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6403",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 62,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 25.2,
    "static_load_kN": 10.8,
    "fatigue_load_limit_kN": 0.84,
    "limiting_speed_rpm": 14000,
    "max_rpm": 14000,
    "weight_g": 270,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6400-series (diameter series 4 of ISO 15) the last two digits encode the bore: 6403 carries bore code 17 = 17 mm. Outside diameter 62 mm and width 17 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 17 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "pulp and paper machinery",
      "medium and heavy industrial drives",
      "large gearboxes",
      "industrial fans and blowers"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Mount this 17 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.",
      "The 64xx heavy section at 17 mm bore (62 mm OD) is built for high-load, lower-speed duty; specifying it in a high-rpm motor gives excess heat and short grease life — use 62/63 there.",
      "The open 6403-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 17×62×17 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 6400-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6403 units.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6400-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 17 mm-wide ring of 6403-NTN drags the lip and overheats it.",
      "The open 6403 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 17 mm bore the 6403 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6403 at 14000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "At 25.2 kN dynamic load rating (C) and 10.8 kN static (C0), 0.84 kN fatigue load limit Cu, 6403 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 270 g, 6403 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 17×62×17 mm envelope of 6403 gives a D/d ratio of 3.65 and 22.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 25.2/10.8 kN load ratings, 0.84 kN fatigue load limit Cu NTN lists the grease limiting speed at 14000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 270 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6403 on the 17×62×17 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6403 in a rated drive.",
      "Standard catalogue stock of 6403 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6403 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6403-NTN bearing?",
        "a": "A 6403-NTN deep-groove ball bearing has a 17 mm bore, 62 mm outer diameter and 17 mm width (0.669 × 2.441 × 0.669 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6400 compare with other series at the same 17 mm bore?",
        "a": "The '4' is the heavy diameter series: 62×17 mm, 22.5 mm radial section at 17 mm bore — the highest-capacity single-row 6xx option here, aimed at lower-speed, high-load shafts."
      },
      {
        "q": "Are 6403 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6403 uses the same ISO 15 envelope (17×62×17 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 6403?",
        "a": "NTN lists the open 6403 under the bare designation 6403; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 17 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6403 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6403 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6403-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 17×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6403-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 17×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6403",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 17×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6403",
      "6403-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6403-ZZ",
    "brand": "NTN",
    "manufacturer_designation": "6403ZZ",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 17,
    "D_mm": 62,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 25.2,
    "static_load_kN": 10.8,
    "fatigue_load_limit_kN": 0.84,
    "limiting_speed_rpm": 14000,
    "max_rpm": 14000,
    "weight_g": 270,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6403-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the heavy 64xx section (diameter series 4 of ISO 15), multiplying bore code 17 by five gives the 17 mm bore; the 62 mm outside diameter and 17 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 17 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6403ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "medium and heavy industrial drives",
      "large gearboxes",
      "industrial fans and blowers",
      "hoists and winches"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "At 17 mm bore the ring mass is significant: heat 6403 on an induction heater (max 120 °C), never over an open flame, and plan puller access or a withdrawal sleeve now for the day it has to come off again.",
      "The 64xx heavy section at 17 mm bore exists for high radial load at moderate rpm; its 62 mm OD and 17 mm width demand a larger housing, and grease life at motor speeds is short — treat it as a low-speed, high-load choice.",
      "ZZ shields are non-contact: 6403-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6403-2RS for that.",
      "Do not wash 6403-ZZ in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Vibration during standstill brinells the raceways of a 17 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 62 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6403-ZZ.",
      "NTN catalogues the shielded version as 6403ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 17 mm bore the 6403 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.",
      "NTN rates 6403 at 14000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 25.2 kN dynamic load rating (C) and 10.8 kN static (C0), 0.84 kN fatigue load limit Cu, 6403 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 270 g, 6403 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 17×62×17 mm envelope of 6403 gives a D/d ratio of 3.65 and 22.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 25.2/10.8 kN load ratings, 0.84 kN fatigue load limit Cu NTN lists the grease limiting speed at 14000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 270 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6403ZZ on the 17×62×17 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6403 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6403-ZZ bearing?",
        "a": "A 6403-ZZ deep-groove ball bearing has a 17 mm bore, 62 mm outer diameter and 17 mm width (0.669 × 2.441 × 0.669 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 6400 compare with other series at the same 17 mm bore?",
        "a": "The '4' is the heavy diameter series: 62×17 mm, 22.5 mm radial section at 17 mm bore — the highest-capacity single-row 6xx option here, aimed at lower-speed, high-load shafts."
      },
      {
        "q": "Are 6403 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6403 uses the same ISO 15 envelope (17×62×17 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6403?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6403ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 17×62×17 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6403ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6403-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 17×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6403-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 17×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6403",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 17×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6403-zz",
      "6403zz",
      "6403-ZZ",
      "6403ZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61804-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6804JR",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 32,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 4.45,
    "static_load_kN": 2.47,
    "fatigue_load_limit_kN": 0.18,
    "limiting_speed_rpm": 21000,
    "max_rpm": 21000,
    "weight_g": 19,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61804 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 04 by five gives the 20 mm bore; the 32 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 20 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "A 20 mm shaft for 61804 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "Only 6.0 mm of radial section separates bore and OD on the 618xx series at 20 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6204.",
      "The open 61804-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 20×32×7 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 61804-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 32 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61804-NTN.",
      "Vibration during standstill brinells the raceways of a 20 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "The open 61804 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 20 mm bore puts 61804 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61804 at 21000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "At 4.45 kN dynamic load rating (C) and 2.47 kN static (C0), 0.18 kN fatigue load limit Cu, 61804 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 19 g, 61804 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 20×32×7 mm envelope of 61804 gives a D/d ratio of 1.60 and 6.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 4.45/2.47 kN load ratings, 0.18 kN fatigue load limit Cu NTN lists the grease limiting speed at 21000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 19 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6804JR on the 20×32×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61804 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61804-NTN bearing?",
        "a": "A 61804-NTN deep-groove ball bearing has a 20 mm bore, 32 mm outer diameter and 7 mm width (0.787 × 1.26 × 0.276 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 61804 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61804 uses the same ISO 15 envelope (20×32×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 61804-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61804-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61804 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 61804?",
        "a": "NTN lists the open 61804 under the bare designation 6804JR; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 20 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6804JR?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61804-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61804-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61804-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6804jr",
      "61804",
      "6804JR",
      "61804-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61804-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6804JRLLU",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 32,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 4.45,
    "static_load_kN": 2.47,
    "fatigue_load_limit_kN": 0.18,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "weight_g": 19,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61804-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 04 by five gives the 20 mm bore; the 32 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 20 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6804JRLLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At a 20 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61804-2RS-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 618xx thin section at 20 mm bore has only a 6.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6204.",
      "Contact seals add drag and heat: 61804-2RS-NTN runs slower and cooler-limited than the open 61804; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 61804-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Never mix components between two 61804-2RS-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the contact-sealed version as 6804JRLLU (suffix RLLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 20 mm bore puts 61804 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61804 at 13000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 4.45 kN dynamic load rating (C) and 2.47 kN static (C0), 0.18 kN fatigue load limit Cu, 61804 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 19 g, 61804 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 20×32×7 mm envelope of 61804 gives a D/d ratio of 1.60 and 6.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 4.45/2.47 kN load ratings, 0.18 kN fatigue load limit Cu NTN lists the grease limiting speed at 13000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 19 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6804JRLLU on the 20×32×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61804 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61804 is listed.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61804-2RS-NTN bearing?",
        "a": "A 61804-2RS-NTN deep-groove ball bearing has a 20 mm bore, 32 mm outer diameter and 7 mm width (0.787 × 1.26 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What internal clearance does 61804-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61804-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61804 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61804-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 20 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 61804?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6804JRLLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×32×7 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6804JRLLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61804-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61804-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61804-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61804-llu",
      "6804jrllu",
      "6804llu",
      "61804-2RS",
      "61804-2rs",
      "6804JRLLU",
      "61804-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61804-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6804JRLLB",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 32,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 4.45,
    "static_load_kN": 2.47,
    "fatigue_load_limit_kN": 0.18,
    "limiting_speed_rpm": 21000,
    "max_rpm": 21000,
    "weight_g": 19,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61804-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 04 by five gives the 20 mm bore; the 32 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 20 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6804JRLLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "A 20 mm shaft for 61804 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 618xx thin section at 20 mm bore has only a 6.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6204.",
      "RSR low-friction seals on 61804-RSR-NTN run faster than contact-seal 61804-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61804-2RS instead.",
      "The non-contact lip of 61804-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 20 mm bore position before relying on it as sealed-for-life.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 7 mm-wide ring of 61804-RSR-NTN drags the lip and overheats it.",
      "Vibration during standstill brinells the raceways of a 20 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues this low-friction non-contact seal as 6804JRLLB (suffix RLLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 20 mm bore puts 61804 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61804 at 21000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 4.45 kN dynamic load rating (C) and 2.47 kN static (C0), 0.18 kN fatigue load limit Cu, 61804 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 19 g, 61804 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 20×32×7 mm envelope of 61804 gives a D/d ratio of 1.60 and 6.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 4.45/2.47 kN load ratings, 0.18 kN fatigue load limit Cu NTN lists the grease limiting speed at 21000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 19 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6804JRLLB on the 20×32×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61804 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Standard catalogue stock of 61804 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61804-RSR-NTN bearing?",
        "a": "A 61804-RSR-NTN deep-groove ball bearing has a 20 mm bore, 32 mm outer diameter and 7 mm width (0.787 × 1.26 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 61800 compare with other series at the same 20 mm bore?",
        "a": "618 is an extra-thin section: 32×7 mm, only 6.0 mm radial section at 20 mm bore, far smaller than a 6204, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "Are 61804 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61804 uses the same ISO 15 envelope (20×32×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61804?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6804JRLLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×32×7 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6804JRLLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61804-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61804-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61804-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61804-llb",
      "6804jrllb",
      "6804llb",
      "61804-RSR",
      "61804-rsr",
      "6804JRLLB",
      "61804-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61804-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6804JRZZ",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 32,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 4.45,
    "static_load_kN": 2.47,
    "fatigue_load_limit_kN": 0.18,
    "limiting_speed_rpm": 21000,
    "max_rpm": 21000,
    "weight_g": 19,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61804-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 04 by five gives the 20 mm bore; the 32 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 20 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6804JRZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "At a 20 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61804-ZZ-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "Only 6.0 mm of radial section separates bore and OD on the 618xx series at 20 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6204.",
      "ZZ shields are non-contact: 61804-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61804-2RS for that.",
      "Do not wash 61804-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Vibration during standstill brinells the raceways of a 20 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "A 20 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues the shielded version as 6804JRZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 20 mm bore puts 61804 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61804 at 21000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 4.45 kN dynamic load rating (C) and 2.47 kN static (C0), 0.18 kN fatigue load limit Cu, 61804 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 19 g, 61804 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 20×32×7 mm envelope of 61804 gives a D/d ratio of 1.60 and 6.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 4.45/2.47 kN load ratings, 0.18 kN fatigue load limit Cu NTN lists the grease limiting speed at 21000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 19 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6804JRZZ on the 20×32×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61804 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61804 is listed.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61804-ZZ-NTN bearing?",
        "a": "A 61804-ZZ-NTN deep-groove ball bearing has a 20 mm bore, 32 mm outer diameter and 7 mm width (0.787 × 1.26 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 61804-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 61800 compare with other series at the same 20 mm bore?",
        "a": "618 is an extra-thin section: 32×7 mm, only 6.0 mm radial section at 20 mm bore, far smaller than a 6204, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "What is the NTN suffix for a sealed 61804?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6804JRZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×32×7 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6804JRZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61804-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61804-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61804-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61804-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×32×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61804-zz",
      "6804jrzz",
      "6804zz",
      "61804-ZZ",
      "6804JRZZ",
      "61804-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61904-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6904",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 37,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 7.05,
    "static_load_kN": 3.7,
    "fatigue_load_limit_kN": 0.29,
    "limiting_speed_rpm": 19000,
    "max_rpm": 19000,
    "weight_g": 36,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61904 carries bore code 04 = 20 mm. Outside diameter 37 mm and width 9 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 20 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "At a 20 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61904-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 619xx thin section (8.5 mm section height at 20 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "The open 61904-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 20×37×9 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 61904-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61904-NTN-C3. No clearance suffix means normal CN clearance.",
      "The housing bore for the 37 mm OD should be round within IT7; an oval bore pinches the outer ring of 61904-NTN and shows up later as two-point loaded raceway wear.",
      "The open 61904 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 20 mm bore puts 61904 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61904 at 19000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 61904 at 7.05 kN dynamic (C) and 3.7 kN static (C0), 0.29 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 36 g, 61904 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 20×37×9 mm envelope of 61904 gives a D/d ratio of 1.85 and 8.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 7.05/3.7 kN load ratings, 0.29 kN fatigue load limit Cu NTN lists the grease limiting speed at 19000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 36 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6904 on the 20×37×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61904 in a rated drive.",
      "Standard catalogue stock of 61904 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61904 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61904-NTN bearing?",
        "a": "A 61904-NTN deep-groove ball bearing has a 20 mm bore, 37 mm outer diameter and 9 mm width (0.787 × 1.457 × 0.354 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 61904 bore code work?",
        "a": "The last two digits of 61904 are bore code 04, giving 04 × 5 = 20 mm bore. The 37 mm outside diameter and 9 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does no suffix on 61904 mean?",
        "a": "A bare 61904 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "What is the NTN order number for an open 61904?",
        "a": "NTN lists the open 61904 under the bare designation 6904; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 20 mm bore envelope."
      },
      {
        "q": "Is 6904 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61904-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61904-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61904",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6904",
      "61904",
      "61904-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61904-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6904LLU",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 37,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 7.05,
    "static_load_kN": 3.7,
    "fatigue_load_limit_kN": 0.29,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 36,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61904-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 04 by five gives the 20 mm bore; the 37 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 20 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6904LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Sizes around 20 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 61904-2RS-NTN.",
      "The 619xx thin section (8.5 mm section height at 20 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "Contact seals add drag and heat: 61904-2RS-NTN runs slower and cooler-limited than the open 61904; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 61904-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "Measure the shaft, do not trust the drawing: a 20 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61904-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6904LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 20 mm bore puts 61904 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61904 at 12000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 61904 at 7.05 kN dynamic (C) and 3.7 kN static (C0), 0.29 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 36 g, 61904 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 20×37×9 mm envelope of 61904 gives a D/d ratio of 1.85 and 8.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 7.05/3.7 kN load ratings, 0.29 kN fatigue load limit Cu NTN lists the grease limiting speed at 12000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 36 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6904LLU on the 20×37×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61904 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61904 is listed.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61904-2RS-NTN bearing?",
        "a": "A 61904-2RS-NTN deep-groove ball bearing has a 20 mm bore, 37 mm outer diameter and 9 mm width (0.787 × 1.457 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 61904 bore code work?",
        "a": "The last two digits of 61904 are bore code 04, giving 04 × 5 = 20 mm bore. The 37 mm outside diameter and 9 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the 2RS suffix on 61904-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "What is the NTN suffix for a sealed 61904?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6904LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×37×9 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61904 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6904LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61904-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61904-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61904",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61904-llu",
      "6904llu",
      "61904-2RS",
      "61904-2rs",
      "6904LLU",
      "61904-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61904-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6904LLB",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 37,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 7.05,
    "static_load_kN": 3.7,
    "fatigue_load_limit_kN": 0.29,
    "limiting_speed_rpm": 19000,
    "max_rpm": 19000,
    "weight_g": 36,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61904 carries bore code 04 = 20 mm. Outside diameter 37 mm and width 9 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 20 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6904LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "A 20 mm shaft for 61904 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 619xx thin section at 20 mm bore (8.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "RSR low-friction seals on 61904-RSR-NTN run faster than contact-seal 61904-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61904-2RS instead.",
      "The low-drag lip of 61904-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "Shaft and housing fillets must clear the bearing chamfer so the 9 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Never mix components between two 61904-RSR-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues this low-friction non-contact seal as 6904LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 20 mm bore puts 61904 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61904 at 19000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 61904 at 7.05 kN dynamic (C) and 3.7 kN static (C0), 0.29 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 36 g, 61904 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 20×37×9 mm envelope of 61904 gives a D/d ratio of 1.85 and 8.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 7.05/3.7 kN load ratings, 0.29 kN fatigue load limit Cu NTN lists the grease limiting speed at 19000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 36 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6904LLB on the 20×37×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61904 in a rated drive.",
      "Order the C3 internal-clearance version (61904 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61904-RSR-NTN bearing?",
        "a": "A 61904-RSR-NTN deep-groove ball bearing has a 20 mm bore, 37 mm outer diameter and 9 mm width (0.787 × 1.457 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 61900 compare with other series at the same 20 mm bore?",
        "a": "619 is a thin section one step above 618: 37×9 mm with an 8.5 mm radial section at 20 mm bore; a 6204 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "Are 61904 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61904 uses the same ISO 15 envelope (20×37×9 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61904?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6904LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×37×9 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61904 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6904LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61904-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61904-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61904",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61904-llb",
      "6904llb",
      "61904-RSR",
      "61904-rsr",
      "6904LLB",
      "61904-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61904-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6904ZZ",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 37,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 7.05,
    "static_load_kN": 3.7,
    "fatigue_load_limit_kN": 0.29,
    "limiting_speed_rpm": 19000,
    "max_rpm": 19000,
    "weight_g": 36,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61904 carries bore code 04 = 20 mm. Outside diameter 37 mm and width 9 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 20 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6904ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "A 20 mm shaft for 61904 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 619xx thin section (8.5 mm section height at 20 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "ZZ shields are non-contact: 61904-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61904-2RS for that.",
      "Shielded 61904-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 9 mm-wide ring of 61904-ZZ-NTN drags the lip and overheats it.",
      "Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues the shielded version as 6904ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 20 mm bore puts 61904 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61904 at 19000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 61904 at 7.05 kN dynamic (C) and 3.7 kN static (C0), 0.29 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 36 g, 61904 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 20×37×9 mm envelope of 61904 gives a D/d ratio of 1.85 and 8.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 7.05/3.7 kN load ratings, 0.29 kN fatigue load limit Cu NTN lists the grease limiting speed at 19000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 36 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6904ZZ on the 20×37×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61904 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Standard catalogue stock of 61904 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61904-ZZ-NTN bearing?",
        "a": "A 61904-ZZ-NTN deep-groove ball bearing has a 20 mm bore, 37 mm outer diameter and 9 mm width (0.787 × 1.457 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 61904-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 61900 compare with other series at the same 20 mm bore?",
        "a": "619 is a thin section one step above 618: 37×9 mm with an 8.5 mm radial section at 20 mm bore; a 6204 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "What is the NTN suffix for a sealed 61904?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6904ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×37×9 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6904ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61904-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61904-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61904-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61904",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×37×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61904-zz",
      "6904zz",
      "61904-ZZ",
      "6904ZZ",
      "61904-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "16004-NTN",
    "brand": "NTN",
    "manufacturer_designation": "16004",
    "series": "16000-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 42,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 8.75,
    "static_load_kN": 4.5,
    "fatigue_load_limit_kN": 0.35,
    "limiting_speed_rpm": 18000,
    "max_rpm": 18000,
    "weight_g": 51,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "16004 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the narrow 160xx section of the ISO 15 general plan, multiplying bore code 04 by five gives the 20 mm bore; the 42 mm outside diameter and 8 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 20 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "electric motors",
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "A 20 mm shaft for 16004 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "Because the 160xx narrow section shares the 42 mm OD of the 6004 at 20 mm bore but is only 8 mm wide, a housing machined for the wider bearing needs a spacer or relocated circlip — never assume width interchangeability.",
      "Storage matters for open bearings: 16004-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 16000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 16004 units.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 16000-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "The housing bore for the 42 mm OD should be round within IT7; an oval bore pinches the outer ring of 16004-NTN and shows up later as two-point loaded raceway wear.",
      "The open 16004 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 20 mm bore puts 16004 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 16004 at 18000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 16004 at 8.75 kN dynamic (C) and 4.5 kN static (C0), 0.35 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 51 g, 16004 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 20×42×8 mm envelope of 16004 gives a D/d ratio of 2.10 and 11.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 8.75/4.5 kN load ratings, 0.35 kN fatigue load limit Cu NTN lists the grease limiting speed at 18000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 51 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 16004 on the 20×42×8 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 16004 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Standard catalogue stock of 16004 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 16004-NTN bearing?",
        "a": "A 16004-NTN deep-groove ball bearing has a 20 mm bore, 42 mm outer diameter and 8 mm width (0.787 × 1.654 × 0.315 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How should 16004-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 20 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 16004-NTN need?",
        "a": "The open 16004-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "What is the NTN order number for an open 16004?",
        "a": "NTN lists the open 16004 under the bare designation 16004; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 20 mm bore envelope."
      },
      {
        "q": "Does NTN offer 16004 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 16004 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "16004",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×42×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "16004",
      "16004-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6004-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6004",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 42,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.4,
    "static_load_kN": 5.05,
    "fatigue_load_limit_kN": 0.35,
    "limiting_speed_rpm": 18000,
    "max_rpm": 18000,
    "weight_g": 69,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6004 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 04 by five gives the 20 mm bore; the 42 mm outside diameter and 12 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 20 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "At a 20 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6004-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "Choosing the 60xx extra-light section saves radial space at 20 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6204 before committing to the smaller envelope.",
      "The open 6004-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 20×42×12 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 6000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6004 units.",
      "The housing bore for the 42 mm OD should be round within IT7; an oval bore pinches the outer ring of 6004-NTN and shows up later as two-point loaded raceway wear.",
      "A 20 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "The open 6004 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 20 mm bore puts 6004 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 6004 at 18000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 6004 at 10.4 kN dynamic (C) and 5.05 kN static (C0), 0.35 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 69 g, 6004 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 20×42×12 mm envelope of 6004 gives a D/d ratio of 2.10 and 11.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 10.4/5.05 kN load ratings, 0.35 kN fatigue load limit Cu NTN lists the grease limiting speed at 18000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 69 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6004 on the 20×42×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6004 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6004 is listed.",
      "Order the C3 internal-clearance version (6004 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6004-NTN bearing?",
        "a": "A 6004-NTN deep-groove ball bearing has a 20 mm bore, 42 mm outer diameter and 12 mm width (0.787 × 1.654 × 0.472 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 6004 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6004 uses the same ISO 15 envelope (20×42×12 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 6004-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6004-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6004 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 6004?",
        "a": "NTN lists the open 6004 under the bare designation 6004; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 20 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6004 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6004 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6004-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6004-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6004-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6004",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6004",
      "6004-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6004-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6004LLU",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 42,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.4,
    "static_load_kN": 5.05,
    "fatigue_load_limit_kN": 0.35,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "weight_g": 69,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6004 carries bore code 04 = 20 mm. Outside diameter 42 mm and width 12 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 20 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6004LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "fans and blowers",
      "electric motors",
      "centrifugal pumps",
      "small gearboxes"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "A 20 mm shaft for 6004 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 60xx extra-light section at 20 mm bore uses a smaller 42 mm OD than a 6204; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "Contact seals add drag and heat: 6004-2RS-NTN runs slower and cooler-limited than the open 6004; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 6004-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "The housing bore for the 42 mm OD should be round within IT7; an oval bore pinches the outer ring of 6004-2RS-NTN and shows up later as two-point loaded raceway wear.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6000-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "NTN catalogues the contact-sealed version as 6004LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 20 mm bore puts 6004 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 11000 r/min the grease limiting speed for 6004 covers most general-purpose industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 6004 at 10.4 kN dynamic (C) and 5.05 kN static (C0), 0.35 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 69 g, 6004 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 20×42×12 mm envelope of 6004 gives a D/d ratio of 2.10 and 11.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 10.4/5.05 kN load ratings, 0.35 kN fatigue load limit Cu NTN lists the grease limiting speed at 11000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 69 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6004LLU on the 20×42×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6004 in a rated drive.",
      "Order the C3 internal-clearance version (6004 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Standard catalogue stock of 6004 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6004-2RS-NTN bearing?",
        "a": "A 6004-2RS-NTN deep-groove ball bearing has a 20 mm bore, 42 mm outer diameter and 12 mm width (0.787 × 1.654 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What lubrication does 6004-2RS-NTN need?",
        "a": "6004-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6004 with a housing grease fitting instead."
      },
      {
        "q": "How does the 6004 bore code work?",
        "a": "The last two digits of 6004 are bore code 04, giving 04 × 5 = 20 mm bore. The 42 mm outside diameter and 12 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6004?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6004LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×42×12 mm ISO 15 envelope."
      },
      {
        "q": "Is 6004LLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6004-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6004-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6004-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6004",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6004-llu",
      "6004llu",
      "6004-2RS",
      "6004-2rs",
      "6004LLU",
      "6004-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6004-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6004LLB",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 42,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.4,
    "static_load_kN": 5.05,
    "fatigue_load_limit_kN": 0.35,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "weight_g": 69,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6004-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 04 by five gives the 20 mm bore; the 42 mm outside diameter and 12 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 20 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6004LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "A 20 mm shaft for 6004 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "Choosing the 60xx extra-light section saves radial space at 20 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6204 before committing to the smaller envelope.",
      "RSR low-friction seals on 6004-RSR-NTN run faster than contact-seal 6004-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6004-2RS instead.",
      "The non-contact lip of 6004-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 20 mm bore position before relying on it as sealed-for-life.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 12 mm-wide ring of 6004-RSR-NTN drags the lip and overheats it.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 42 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6004-RSR-NTN.",
      "NTN catalogues this low-friction non-contact seal as 6004LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 20 mm bore puts 6004 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 6004 at 13000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6004 at 10.4 kN dynamic (C) and 5.05 kN static (C0), 0.35 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 69 g, 6004 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 20×42×12 mm envelope of 6004 gives a D/d ratio of 2.10 and 11.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 10.4/5.05 kN load ratings, 0.35 kN fatigue load limit Cu NTN lists the grease limiting speed at 13000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 69 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6004LLB on the 20×42×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6004 in a rated drive.",
      "Order the C3 internal-clearance version (6004 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6004-RSR-NTN bearing?",
        "a": "A 6004-RSR-NTN deep-groove ball bearing has a 20 mm bore, 42 mm outer diameter and 12 mm width (0.787 × 1.654 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6000 compare with other series at the same 20 mm bore?",
        "a": "The second digit is the diameter series: 60 is the smallest standard section (42×12 mm, 11.0 mm radial section) at 20 mm bore — below 62/63/64 in load capacity, for light loads in compact spaces."
      },
      {
        "q": "Are 6004 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6004 uses the same ISO 15 envelope (20×42×12 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6004?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6004LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×42×12 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6004 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6004LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6004-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6004-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6004-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6004",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6004-llb",
      "6004llb",
      "6004-RSR",
      "6004-rsr",
      "6004LLB",
      "6004-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6004-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6004ZZ",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 42,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.4,
    "static_load_kN": 5.05,
    "fatigue_load_limit_kN": 0.35,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "weight_g": 69,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6004 carries bore code 04 = 20 mm. Outside diameter 42 mm and width 12 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 20 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6004ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "fans and blowers",
      "electric motors",
      "centrifugal pumps",
      "small gearboxes"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "At a 20 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6004-ZZ-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "Choosing the 60xx extra-light section saves radial space at 20 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6204 before committing to the smaller envelope.",
      "ZZ shields are non-contact: 6004-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6004-2RS for that.",
      "Do not wash 6004-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Never mix components between two 6004-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "A 20 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues the shielded version as 6004ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 20 mm bore puts 6004 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 6004 at 13000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6004 at 10.4 kN dynamic (C) and 5.05 kN static (C0), 0.35 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 69 g, 6004 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 20×42×12 mm envelope of 6004 gives a D/d ratio of 2.10 and 11.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 10.4/5.05 kN load ratings, 0.35 kN fatigue load limit Cu NTN lists the grease limiting speed at 13000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 69 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6004ZZ on the 20×42×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6004 in a rated drive.",
      "Standard catalogue stock of 6004 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Order the C3 internal-clearance version (6004 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6004-ZZ-NTN bearing?",
        "a": "A 6004-ZZ-NTN deep-groove ball bearing has a 20 mm bore, 42 mm outer diameter and 12 mm width (0.787 × 1.654 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How should 6004-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 20 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6004-ZZ-NTN need?",
        "a": "6004-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "What is the NTN suffix for a sealed 6004?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6004ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×42×12 mm ISO 15 envelope."
      },
      {
        "q": "Is 6004ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6004-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6004-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6004-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6004-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6004",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×42×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6004-zz",
      "6004zz",
      "6004-ZZ",
      "6004ZZ",
      "6004-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6204-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6204",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 47,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 14.2,
    "static_load_kN": 6.65,
    "fatigue_load_limit_kN": 0.51,
    "limiting_speed_rpm": 16000,
    "max_rpm": 16000,
    "weight_g": 106,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6204 carries bore code 04 = 20 mm. Outside diameter 47 mm and width 14 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 20 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "electric motors",
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Sizes around 20 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6204-NTN.",
      "The 62xx light series is the default general-purpose section at 20 mm bore; before upgrading to a 6304 for extra capacity, confirm the housing accepts a 47 mm OD and 14 mm width — it is not a drop-in swap.",
      "The open 6204-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 20×47×14 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 6200-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6204 units.",
      "Vibration during standstill brinells the raceways of a 20 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Never mix components between two 6204-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "The open 6204 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 20 mm bore puts 6204 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 6204 at 16000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 6204 at 14.2 kN dynamic (C) and 6.65 kN static (C0), 0.51 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 106 g, 6204 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 20×47×14 mm envelope of 6204 gives a D/d ratio of 2.35 and 13.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 14.2/6.65 kN load ratings, 0.51 kN fatigue load limit Cu NTN lists the grease limiting speed at 16000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 106 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6204 on the 20×47×14 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6204 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Order the C3 internal-clearance version (6204 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6204-NTN bearing?",
        "a": "A 6204-NTN deep-groove ball bearing has a 20 mm bore, 47 mm outer diameter and 14 mm width (0.787 × 1.85 × 0.551 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What internal clearance does 6204-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6204-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6204 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6204-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 20 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN order number for an open 6204?",
        "a": "NTN lists the open 6204 under the bare designation 6204; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 20 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6204?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6204-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6204-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6204-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6204",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6204",
      "6204-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6204-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6204LLU",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 47,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 14.2,
    "static_load_kN": 6.65,
    "fatigue_load_limit_kN": 0.51,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "weight_g": 106,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6204-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 04 by five gives the 20 mm bore; the 47 mm outside diameter and 14 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 20 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6204LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "A 20 mm shaft for 6204 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 62xx light series is the default general-purpose section at 20 mm bore; before upgrading to a 6304 for extra capacity, confirm the housing accepts a 47 mm OD and 14 mm width — it is not a drop-in swap.",
      "Heat is the enemy of the sealed 6204-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 6204-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6200-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Do not quieten a noisy bearing by preloading it: the 6200-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues the contact-sealed version as 6204LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 20 mm bore puts 6204 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 10000 r/min the grease limiting speed for 6204 covers most general-purpose industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 6204 at 14.2 kN dynamic (C) and 6.65 kN static (C0), 0.51 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 106 g, 6204 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 20×47×14 mm envelope of 6204 gives a D/d ratio of 2.35 and 13.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 14.2/6.65 kN load ratings, 0.51 kN fatigue load limit Cu NTN lists the grease limiting speed at 10000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 106 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6204LLU on the 20×47×14 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6204 in a rated drive.",
      "Order the C3 internal-clearance version (6204 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Standard catalogue stock of 6204 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6204-2RS-NTN bearing?",
        "a": "A 6204-2RS-NTN deep-groove ball bearing has a 20 mm bore, 47 mm outer diameter and 14 mm width (0.787 × 1.85 × 0.551 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What internal clearance does 6204-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6204-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6204 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6204-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 20 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 6204?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6204LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×47×14 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6204 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6204LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6204-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6204-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6204-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6204",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6204-llu",
      "6204llu",
      "6204-2RS",
      "6204-2rs",
      "6204LLU",
      "6204-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6204-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6204LLB",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 47,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 14.2,
    "static_load_kN": 6.65,
    "fatigue_load_limit_kN": 0.51,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 106,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6204-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 04 by five gives the 20 mm bore; the 47 mm outside diameter and 14 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 20 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6204LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Sizes around 20 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6204-RSR-NTN.",
      "At 20 mm bore the 62xx light series is the workhorse section; its 47×14 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "RSR low-friction seals on 6204-RSR-NTN run faster than contact-seal 6204-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6204-2RS instead.",
      "The low-drag lip of 6204-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "Vibration during standstill brinells the raceways of a 20 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Never mix components between two 6204-RSR-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues this low-friction non-contact seal as 6204LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 20 mm bore puts 6204 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 6204 at 12000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6204 at 14.2 kN dynamic (C) and 6.65 kN static (C0), 0.51 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 106 g, 6204 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 20×47×14 mm envelope of 6204 gives a D/d ratio of 2.35 and 13.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 14.2/6.65 kN load ratings, 0.51 kN fatigue load limit Cu NTN lists the grease limiting speed at 12000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 106 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6204LLB on the 20×47×14 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6204 in a rated drive.",
      "Order the C3 internal-clearance version (6204 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Standard catalogue stock of 6204 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6204-RSR-NTN bearing?",
        "a": "A 6204-RSR-NTN deep-groove ball bearing has a 20 mm bore, 47 mm outer diameter and 14 mm width (0.787 × 1.85 × 0.551 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6200 compare with other series at the same 20 mm bore?",
        "a": "The '2' is the light diameter series: 47×14 mm with a 13.5 mm radial section at 20 mm bore. A 6304 on the same bore is larger and higher-rated; a 6004 is smaller and lower-rated."
      },
      {
        "q": "Are 6204 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6204 uses the same ISO 15 envelope (20×47×14 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6204?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6204LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×47×14 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6204LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6204-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6204-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6204-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6204",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6204-llb",
      "6204llb",
      "6204-RSR",
      "6204-rsr",
      "6204LLB",
      "6204-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6204-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6204ZZ",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 47,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 14.2,
    "static_load_kN": 6.65,
    "fatigue_load_limit_kN": 0.51,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 106,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6204-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 04 by five gives the 20 mm bore; the 47 mm outside diameter and 14 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 20 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6204ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At a 20 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6204-ZZ-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "At 20 mm bore the 62xx light series is the workhorse section; its 47×14 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "ZZ shields are non-contact: 6204-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6204-2RS for that.",
      "Do not wash 6204-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6200-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues the shielded version as 6204ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 20 mm bore puts 6204 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 6204 at 12000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 6204 at 14.2 kN dynamic (C) and 6.65 kN static (C0), 0.51 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 106 g, 6204 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 20×47×14 mm envelope of 6204 gives a D/d ratio of 2.35 and 13.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 14.2/6.65 kN load ratings, 0.51 kN fatigue load limit Cu NTN lists the grease limiting speed at 12000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 106 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6204ZZ on the 20×47×14 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6204 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6204 is listed.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6204-ZZ-NTN bearing?",
        "a": "A 6204-ZZ-NTN deep-groove ball bearing has a 20 mm bore, 47 mm outer diameter and 14 mm width (0.787 × 1.85 × 0.551 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 6204 bore code work?",
        "a": "The last two digits of 6204 are bore code 04, giving 04 × 5 = 20 mm bore. The 47 mm outside diameter and 14 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the ZZ suffix on 6204-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "What is the NTN suffix for a sealed 6204?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6204ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×47×14 mm ISO 15 envelope."
      },
      {
        "q": "Is 6204ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6204-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6204-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6204-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6204-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6204",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×47×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6204-zz",
      "6204zz",
      "6204-ZZ",
      "6204ZZ",
      "6204-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6304-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6304",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 52,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 17.6,
    "static_load_kN": 7.9,
    "fatigue_load_limit_kN": 0.61,
    "limiting_speed_rpm": 14000,
    "max_rpm": 14000,
    "weight_g": 144,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6304 carries bore code 04 = 20 mm. Outside diameter 52 mm and width 15 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 20 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers",
      "electric motors"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Sizes around 20 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6304-NTN.",
      "The 63xx medium series gains rating at 20 mm bore through a 52 mm OD and 15 mm width; the heavier rolling elements also trade away some speed versus a 6204.",
      "The open 6304-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 20×52×15 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6304-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Measure the shaft, do not trust the drawing: a 20 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6304-NTN.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "The open 6304 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 20 mm bore puts 6304 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 6304 at 14000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "At 17.6 kN dynamic load rating (C) and 7.9 kN static (C0), 0.61 kN fatigue load limit Cu, 6304 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 144 g, 6304 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 20×52×15 mm envelope of 6304 gives a D/d ratio of 2.60 and 16.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 17.6/7.9 kN load ratings, 0.61 kN fatigue load limit Cu NTN lists the grease limiting speed at 14000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 144 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6304 on the 20×52×15 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6304 in a rated drive.",
      "Standard catalogue stock of 6304 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6304 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6304-NTN bearing?",
        "a": "A 6304-NTN deep-groove ball bearing has a 20 mm bore, 52 mm outer diameter and 15 mm width (0.787 × 2.047 × 0.591 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6304 bore code work?",
        "a": "The last two digits of 6304 are bore code 04, giving 04 × 5 = 20 mm bore. The 52 mm outside diameter and 15 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does no suffix on 6304 mean?",
        "a": "A bare 6304 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "What is the NTN order number for an open 6304?",
        "a": "NTN lists the open 6304 under the bare designation 6304; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 20 mm bore envelope."
      },
      {
        "q": "Is 6304 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6304-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6304-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6304-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6304",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6304",
      "6304-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6304-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6304LLU",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 52,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 17.6,
    "static_load_kN": 7.9,
    "fatigue_load_limit_kN": 0.61,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "weight_g": 144,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6304-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 04 by five gives the 20 mm bore; the 52 mm outside diameter and 15 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 20 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6304LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "A 20 mm shaft for 6304 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 63xx medium series gains rating at 20 mm bore through a 52 mm OD and 15 mm width; the heavier rolling elements also trade away some speed versus a 6204.",
      "Heat is the enemy of the sealed 6304-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 6304-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "The housing bore for the 52 mm OD should be round within IT7; an oval bore pinches the outer ring of 6304-2RS-NTN and shows up later as two-point loaded raceway wear.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6300-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "NTN catalogues the contact-sealed version as 6304LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 20 mm bore puts 6304 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 10000 r/min the grease limiting speed for 6304 covers most general-purpose industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "At 17.6 kN dynamic load rating (C) and 7.9 kN static (C0), 0.61 kN fatigue load limit Cu, 6304 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 144 g, 6304 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 20×52×15 mm envelope of 6304 gives a D/d ratio of 2.60 and 16.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 17.6/7.9 kN load ratings, 0.61 kN fatigue load limit Cu NTN lists the grease limiting speed at 10000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 144 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6304LLU on the 20×52×15 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6304 in a rated drive.",
      "Order the C3 internal-clearance version (6304 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6304-2RS-NTN bearing?",
        "a": "A 6304-2RS-NTN deep-groove ball bearing has a 20 mm bore, 52 mm outer diameter and 15 mm width (0.787 × 2.047 × 0.591 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What does the 2RS suffix on 6304-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "How does the 6300 compare with other series at the same 20 mm bore?",
        "a": "The '3' is the medium diameter series: 52×15 mm, 16.0 mm radial section at 20 mm bore, carrying more load than a 6204 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "What is the NTN suffix for a sealed 6304?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6304LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×52×15 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6304LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6304-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6304-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6304-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6304",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6304-llu",
      "6304llu",
      "6304-2RS",
      "6304-2rs",
      "6304LLU",
      "6304-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6304-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6304LLB",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 52,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 17.6,
    "static_load_kN": 7.9,
    "fatigue_load_limit_kN": 0.61,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 144,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6304 carries bore code 04 = 20 mm. Outside diameter 52 mm and width 15 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 20 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6304LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At a 20 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6304-RSR-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 63xx medium section at 20 mm bore gains dynamic rating through larger rolling elements on a 52 mm OD; the penalty is mass and a lower limiting speed than the 6204 — do not specify it for speed-critical shafts.",
      "RSR low-friction seals on 6304-RSR-NTN run faster than contact-seal 6304-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6304-2RS instead.",
      "The non-contact lip of 6304-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 20 mm bore position before relying on it as sealed-for-life.",
      "The housing bore for the 52 mm OD should be round within IT7; an oval bore pinches the outer ring of 6304-RSR-NTN and shows up later as two-point loaded raceway wear.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6300-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "NTN catalogues this low-friction non-contact seal as 6304LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 20 mm bore puts 6304 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 6304 at 12000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 17.6 kN dynamic load rating (C) and 7.9 kN static (C0), 0.61 kN fatigue load limit Cu, 6304 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 144 g, 6304 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 20×52×15 mm envelope of 6304 gives a D/d ratio of 2.60 and 16.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 17.6/7.9 kN load ratings, 0.61 kN fatigue load limit Cu NTN lists the grease limiting speed at 12000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 144 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6304LLB on the 20×52×15 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6304 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6304-RSR-NTN bearing?",
        "a": "A 6304-RSR-NTN deep-groove ball bearing has a 20 mm bore, 52 mm outer diameter and 15 mm width (0.787 × 2.047 × 0.591 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How should 6304-RSR-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 20 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6304-RSR-NTN need?",
        "a": "6304-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6304 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 6304?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6304LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×52×15 mm ISO 15 envelope."
      },
      {
        "q": "Is 6304LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6304-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6304-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6304-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6304",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6304-llb",
      "6304llb",
      "6304-RSR",
      "6304-rsr",
      "6304LLB",
      "6304-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6304-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6304ZZ",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 52,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 17.6,
    "static_load_kN": 7.9,
    "fatigue_load_limit_kN": 0.61,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 144,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6304-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 04 by five gives the 20 mm bore; the 52 mm outside diameter and 15 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 20 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6304ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers",
      "electric motors"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Sizes around 20 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6304-ZZ-NTN.",
      "The 63xx medium series gains rating at 20 mm bore through a 52 mm OD and 15 mm width; the heavier rolling elements also trade away some speed versus a 6204.",
      "ZZ shields are non-contact: 6304-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6304-2RS for that.",
      "Do not wash 6304-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6300-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Vibration during standstill brinells the raceways of a 20 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues the shielded version as 6304ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 20 mm bore puts 6304 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 6304 at 12000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 17.6 kN dynamic load rating (C) and 7.9 kN static (C0), 0.61 kN fatigue load limit Cu, 6304 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 144 g, 6304 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 20×52×15 mm envelope of 6304 gives a D/d ratio of 2.60 and 16.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 17.6/7.9 kN load ratings, 0.61 kN fatigue load limit Cu NTN lists the grease limiting speed at 12000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 144 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6304ZZ on the 20×52×15 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6304 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Order the C3 internal-clearance version (6304 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6304-ZZ-NTN bearing?",
        "a": "A 6304-ZZ-NTN deep-groove ball bearing has a 20 mm bore, 52 mm outer diameter and 15 mm width (0.787 × 2.047 × 0.591 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How should 6304-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 20 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6304-ZZ-NTN need?",
        "a": "6304-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "What is the NTN suffix for a sealed 6304?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6304ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×52×15 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6304 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6304ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6304-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6304-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6304-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6304-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6304",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=4",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6304-zz",
      "6304zz",
      "6304-ZZ",
      "6304ZZ",
      "6304-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6404-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6404",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 72,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 31.5,
    "static_load_kN": 13.9,
    "fatigue_load_limit_kN": 1.09,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6404 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the heavy 64xx section (diameter series 4 of ISO 15), multiplying bore code 04 by five gives the 20 mm bore; the 72 mm outside diameter and 19 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 20 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "fans and blowers",
      "electric motors",
      "centrifugal pumps",
      "small gearboxes"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "A 20 mm shaft for 6404 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 64xx heavy section at 20 mm bore exists for high radial load at moderate rpm; its 72 mm OD and 19 mm width demand a larger housing, and grease life at motor speeds is short — treat it as a low-speed, high-load choice.",
      "The open 6404-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 20×72×19 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6404-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6404-NTN-C3. No clearance suffix means normal CN clearance.",
      "Shaft and housing fillets must clear the bearing chamfer so the 19 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "The open 6404 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 20 mm bore puts 6404 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 6404 at 12000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "At 31.5 kN dynamic load rating (C) and 13.9 kN static (C0), 1.09 kN fatigue load limit Cu, 6404 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 400 g, 6404 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 20×72×19 mm envelope of 6404 gives a D/d ratio of 3.60 and 26.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 31.5/13.9 kN load ratings, 1.09 kN fatigue load limit Cu NTN lists the grease limiting speed at 12000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 400 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6404 on the 20×72×19 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6404 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Order the C3 internal-clearance version (6404 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6404-NTN bearing?",
        "a": "A 6404-NTN deep-groove ball bearing has a 20 mm bore, 72 mm outer diameter and 19 mm width (0.787 × 2.835 × 0.748 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What internal clearance does 6404-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6404-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6404 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6404-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 20 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN order number for an open 6404?",
        "a": "NTN lists the open 6404 under the bare designation 6404; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 20 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6404 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6404 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6404-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 20×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6404-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 20×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6404",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 20×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6404",
      "6404-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6404-ZZ",
    "brand": "NTN",
    "manufacturer_designation": "6404ZZ",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 20,
    "D_mm": 72,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 31.5,
    "static_load_kN": 13.9,
    "fatigue_load_limit_kN": 1.09,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 400,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6400-series (diameter series 4 of ISO 15) the last two digits encode the bore: 6404 carries bore code 04 = 20 mm. Outside diameter 72 mm and width 19 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 20 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6404ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Sizes around 20 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6404-ZZ.",
      "The 64xx heavy section at 20 mm bore (72 mm OD) is built for high-load, lower-speed duty; specifying it in a high-rpm motor gives excess heat and short grease life — use 62/63 there.",
      "ZZ shields are non-contact: 6404-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6404-2RS for that.",
      "Shielded 6404-ZZ units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Never mix components between two 6404-ZZ units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "The housing bore for the 72 mm OD should be round within IT7; an oval bore pinches the outer ring of 6404-ZZ and shows up later as two-point loaded raceway wear.",
      "NTN catalogues the shielded version as 6404ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 20 mm bore puts 6404 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 6404 at 12000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 31.5 kN dynamic load rating (C) and 13.9 kN static (C0), 1.09 kN fatigue load limit Cu, 6404 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 400 g, 6404 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 20×72×19 mm envelope of 6404 gives a D/d ratio of 3.60 and 26.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 31.5/13.9 kN load ratings, 1.09 kN fatigue load limit Cu NTN lists the grease limiting speed at 12000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 400 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6404ZZ on the 20×72×19 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6404 in a rated drive.",
      "Standard catalogue stock of 6404 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6404 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6404-ZZ bearing?",
        "a": "A 6404-ZZ deep-groove ball bearing has a 20 mm bore, 72 mm outer diameter and 19 mm width (0.787 × 2.835 × 0.748 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What lubrication does 6404-ZZ need?",
        "a": "6404-ZZ is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "How does the 6404 bore code work?",
        "a": "The last two digits of 6404 are bore code 04, giving 04 × 5 = 20 mm bore. The 72 mm outside diameter and 19 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6404?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6404ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 20×72×19 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6404ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6404-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 20×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6404-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 20×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6404",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 20×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6404-zz",
      "6404zz",
      "6404-ZZ",
      "6404ZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61805-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6805JR",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 37,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 4.75,
    "static_load_kN": 2.95,
    "fatigue_load_limit_kN": 0.21,
    "limiting_speed_rpm": 18000,
    "max_rpm": 18000,
    "weight_g": 22,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61805 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 05 by five gives the 25 mm bore; the 37 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 25 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "A 25 mm shaft for 61805 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 618xx thin section at 25 mm bore has only a 6.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6205.",
      "Storage matters for open bearings: 61805-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 61800-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61805 units.",
      "Shaft and housing fillets must clear the bearing chamfer so the 7 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "The open 61805 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 25 mm bore puts 61805 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61805 at 18000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "At 4.75 kN dynamic load rating (C) and 2.95 kN static (C0), 0.21 kN fatigue load limit Cu, 61805 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 22 g, 61805 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 25×37×7 mm envelope of 61805 gives a D/d ratio of 1.48 and 6.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 4.75/2.95 kN load ratings, 0.21 kN fatigue load limit Cu NTN lists the grease limiting speed at 18000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 22 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6805JR on the 25×37×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61805 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61805 is listed.",
      "Order the C3 internal-clearance version (61805 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61805-NTN bearing?",
        "a": "A 61805-NTN deep-groove ball bearing has a 25 mm bore, 37 mm outer diameter and 7 mm width (0.984 × 1.457 × 0.276 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What internal clearance does 61805-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61805-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61805 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61805-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 25 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN order number for an open 61805?",
        "a": "NTN lists the open 61805 under the bare designation 6805JR; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 25 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6805JR?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61805-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61805-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61805-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6805jr",
      "61805",
      "6805JR",
      "61805-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61805-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6805JRLLU",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 37,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 4.75,
    "static_load_kN": 2.95,
    "fatigue_load_limit_kN": 0.21,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "weight_g": 22,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61805 carries bore code 05 = 25 mm. Outside diameter 37 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 25 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6805JRLLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Sizes around 25 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 61805-2RS-NTN.",
      "Only 6.0 mm of radial section separates bore and OD on the 618xx series at 25 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6205.",
      "Contact seals add drag and heat: 61805-2RS-NTN runs slower and cooler-limited than the open 61805; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 61805-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 7 mm-wide ring of 61805-2RS-NTN drags the lip and overheats it.",
      "A 25 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues the contact-sealed version as 6805JRLLU (suffix RLLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 25 mm bore puts 61805 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 10000 r/min the grease limiting speed for 61805 covers most general-purpose industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "At 4.75 kN dynamic load rating (C) and 2.95 kN static (C0), 0.21 kN fatigue load limit Cu, 61805 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 22 g, 61805 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 25×37×7 mm envelope of 61805 gives a D/d ratio of 1.48 and 6.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 4.75/2.95 kN load ratings, 0.21 kN fatigue load limit Cu NTN lists the grease limiting speed at 10000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 22 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6805JRLLU on the 25×37×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61805 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61805 is listed.",
      "Standard catalogue stock of 61805 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61805-2RS-NTN bearing?",
        "a": "A 61805-2RS-NTN deep-groove ball bearing has a 25 mm bore, 37 mm outer diameter and 7 mm width (0.984 × 1.457 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What lubrication does 61805-2RS-NTN need?",
        "a": "61805-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61805 with a housing grease fitting instead."
      },
      {
        "q": "How does the 61805 bore code work?",
        "a": "The last two digits of 61805 are bore code 05, giving 05 × 5 = 25 mm bore. The 37 mm outside diameter and 7 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 61805?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6805JRLLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 25×37×7 mm ISO 15 envelope."
      },
      {
        "q": "Is 6805JRLLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61805-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61805-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61805-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61805-llu",
      "6805jrllu",
      "6805llu",
      "61805-2RS",
      "61805-2rs",
      "6805JRLLU",
      "61805-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61805-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6805JRLLB",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 37,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 4.75,
    "static_load_kN": 2.95,
    "fatigue_load_limit_kN": 0.21,
    "limiting_speed_rpm": 18000,
    "max_rpm": 18000,
    "weight_g": 22,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61805-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 05 by five gives the 25 mm bore; the 37 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 25 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6805JRLLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "A 25 mm shaft for 61805 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "Only 6.0 mm of radial section separates bore and OD on the 618xx series at 25 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6205.",
      "RSR low-friction seals on 61805-RSR-NTN run faster than contact-seal 61805-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61805-2RS instead.",
      "The low-drag lip of 61805-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "Do not quieten a noisy bearing by preloading it: the 61800-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "Shaft and housing fillets must clear the bearing chamfer so the 7 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues this low-friction non-contact seal as 6805JRLLB (suffix RLLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 25 mm bore puts 61805 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61805 at 18000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 4.75 kN dynamic load rating (C) and 2.95 kN static (C0), 0.21 kN fatigue load limit Cu, 61805 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 22 g, 61805 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 25×37×7 mm envelope of 61805 gives a D/d ratio of 1.48 and 6.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 4.75/2.95 kN load ratings, 0.21 kN fatigue load limit Cu NTN lists the grease limiting speed at 18000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 22 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6805JRLLB on the 25×37×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61805 in a rated drive.",
      "Order the C3 internal-clearance version (61805 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Standard catalogue stock of 61805 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61805-RSR-NTN bearing?",
        "a": "A 61805-RSR-NTN deep-groove ball bearing has a 25 mm bore, 37 mm outer diameter and 7 mm width (0.984 × 1.457 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "Are 61805 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61805 uses the same ISO 15 envelope (25×37×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 61805-RSR-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61805-RSR-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61805 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 61805?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6805JRLLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 25×37×7 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61805 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6805JRLLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61805-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61805-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61805-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61805-llb",
      "6805jrllb",
      "6805llb",
      "61805-RSR",
      "61805-rsr",
      "6805JRLLB",
      "61805-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61805-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6805JRZZ",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 37,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 4.75,
    "static_load_kN": 2.95,
    "fatigue_load_limit_kN": 0.21,
    "limiting_speed_rpm": 18000,
    "max_rpm": 18000,
    "weight_g": 22,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61805-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 05 by five gives the 25 mm bore; the 37 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 25 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6805JRZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "A 25 mm shaft for 61805 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "Only 6.0 mm of radial section separates bore and OD on the 618xx series at 25 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6205.",
      "ZZ shields are non-contact: 61805-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61805-2RS for that.",
      "Do not wash 61805-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 37 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61805-ZZ-NTN.",
      "NTN catalogues the shielded version as 6805JRZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 25 mm bore puts 61805 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61805 at 18000 r/min grease limiting speed — this is a high-speed electric-motor range; keep the grease fill at 20–30% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "At 4.75 kN dynamic load rating (C) and 2.95 kN static (C0), 0.21 kN fatigue load limit Cu, 61805 is a light-load bearing: the L10 life at catalogue C is short above a few kN of equivalent load, so size up to a 62-series on the same bore if the application sees shock or frequent starts.",
      "At only 22 g, 61805 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 25×37×7 mm envelope of 61805 gives a D/d ratio of 1.48 and 6.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 4.75/2.95 kN load ratings, 0.21 kN fatigue load limit Cu NTN lists the grease limiting speed at 18000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 22 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6805JRZZ on the 25×37×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61805 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61805-ZZ-NTN bearing?",
        "a": "A 61805-ZZ-NTN deep-groove ball bearing has a 25 mm bore, 37 mm outer diameter and 7 mm width (0.984 × 1.457 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "Are 61805 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61805 uses the same ISO 15 envelope (25×37×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 61805-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61805-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61805 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 61805?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6805JRZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 25×37×7 mm ISO 15 envelope."
      },
      {
        "q": "Is 6805JRZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61805-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61805-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61805-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61805-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×37×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61805-zz",
      "6805jrzz",
      "6805zz",
      "61805-ZZ",
      "6805JRZZ",
      "61805-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61905-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6905",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 42,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 7.8,
    "static_load_kN": 4.55,
    "fatigue_load_limit_kN": 0.34,
    "limiting_speed_rpm": 16000,
    "max_rpm": 16000,
    "weight_g": 42,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61905 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 05 by five gives the 25 mm bore; the 42 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 25 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "At a 25 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61905-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 619xx thin section at 25 mm bore (8.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "The open 61905-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 25×42×9 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 61900-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61905 units.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 9 mm-wide ring of 61905-NTN drags the lip and overheats it.",
      "Shaft and housing fillets must clear the bearing chamfer so the 9 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "The open 61905 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 25 mm bore puts 61905 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61905 at 16000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 61905 at 7.8 kN dynamic (C) and 4.55 kN static (C0), 0.34 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 42 g, 61905 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 25×42×9 mm envelope of 61905 gives a D/d ratio of 1.68 and 8.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 7.8/4.55 kN load ratings, 0.34 kN fatigue load limit Cu NTN lists the grease limiting speed at 16000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 42 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6905 on the 25×42×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61905 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61905 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61905-NTN bearing?",
        "a": "A 61905-NTN deep-groove ball bearing has a 25 mm bore, 42 mm outer diameter and 9 mm width (0.984 × 1.654 × 0.354 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What does no suffix on 61905 mean?",
        "a": "A bare 61905 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "How does the 61900 compare with other series at the same 25 mm bore?",
        "a": "619 is a thin section one step above 618: 42×9 mm with an 8.5 mm radial section at 25 mm bore; a 6205 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "What is the NTN order number for an open 61905?",
        "a": "NTN lists the open 61905 under the bare designation 6905; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 25 mm bore envelope."
      },
      {
        "q": "Is 6905 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61905-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61905-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6905",
      "61905",
      "61905-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61905-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6905LLU",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 42,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 7.8,
    "static_load_kN": 4.55,
    "fatigue_load_limit_kN": 0.34,
    "limiting_speed_rpm": 9800,
    "max_rpm": 9800,
    "weight_g": 42,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61905-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 05 by five gives the 25 mm bore; the 42 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 25 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6905LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Sizes around 25 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 61905-2RS-NTN.",
      "The 619xx thin section (8.5 mm section height at 25 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "Contact seals add drag and heat: 61905-2RS-NTN runs slower and cooler-limited than the open 61905; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 61905-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61905-2RS-NTN-C3. No clearance suffix means normal CN clearance.",
      "Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues the contact-sealed version as 6905LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 25 mm bore puts 61905 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 9800 r/min the grease limiting speed for 61905 covers most general-purpose industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 61905 at 7.8 kN dynamic (C) and 4.55 kN static (C0), 0.34 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 42 g, 61905 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 25×42×9 mm envelope of 61905 gives a D/d ratio of 1.68 and 8.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 7.8/4.55 kN load ratings, 0.34 kN fatigue load limit Cu NTN lists the grease limiting speed at 9800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 42 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6905LLU on the 25×42×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61905 in a rated drive.",
      "Order the C3 internal-clearance version (61905 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61905 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61905-2RS-NTN bearing?",
        "a": "A 61905-2RS-NTN deep-groove ball bearing has a 25 mm bore, 42 mm outer diameter and 9 mm width (0.984 × 1.654 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What internal clearance does 61905-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61905-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61905 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61905-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 25 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 61905?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6905LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 25×42×9 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6905LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61905-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61905-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61905-llu",
      "6905llu",
      "61905-2RS",
      "61905-2rs",
      "6905LLU",
      "61905-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61905-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6905LLB",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 42,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 7.8,
    "static_load_kN": 4.55,
    "fatigue_load_limit_kN": 0.34,
    "limiting_speed_rpm": 11700,
    "max_rpm": 11700,
    "weight_g": 42,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61905 carries bore code 05 = 25 mm. Outside diameter 42 mm and width 9 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 25 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6905LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "At a 25 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61905-RSR-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 619xx thin section at 25 mm bore (8.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "RSR low-friction seals on 61905-RSR-NTN run faster than contact-seal 61905-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61905-2RS instead.",
      "The low-drag lip of 61905-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "Vibration during standstill brinells the raceways of a 25 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "A 25 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues this low-friction non-contact seal as 6905LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 25 mm bore puts 61905 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 11700 r/min the grease limiting speed for 61905 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61905 at 7.8 kN dynamic (C) and 4.55 kN static (C0), 0.34 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 42 g, 61905 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 25×42×9 mm envelope of 61905 gives a D/d ratio of 1.68 and 8.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 7.8/4.55 kN load ratings, 0.34 kN fatigue load limit Cu NTN lists the grease limiting speed at 11700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 42 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6905LLB on the 25×42×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61905 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61905-RSR-NTN bearing?",
        "a": "A 61905-RSR-NTN deep-groove ball bearing has a 25 mm bore, 42 mm outer diameter and 9 mm width (0.984 × 1.654 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "Are 61905 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61905 uses the same ISO 15 envelope (25×42×9 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 61905-RSR-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61905-RSR-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61905 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 61905?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6905LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 25×42×9 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6905LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61905-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61905-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61905-llb",
      "6905llb",
      "61905-RSR",
      "61905-rsr",
      "6905LLB",
      "61905-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61905-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6905ZZ",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 42,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 7.8,
    "static_load_kN": 4.55,
    "fatigue_load_limit_kN": 0.34,
    "limiting_speed_rpm": 11700,
    "max_rpm": 11700,
    "weight_g": 42,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61905-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 05 by five gives the 25 mm bore; the 42 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 25 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6905ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "A 25 mm shaft for 61905 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 619xx thin section (8.5 mm section height at 25 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "Do not wash 61905-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 61905-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "The housing bore for the 42 mm OD should be round within IT7; an oval bore pinches the outer ring of 61905-ZZ-NTN and shows up later as two-point loaded raceway wear.",
      "NTN catalogues the shielded version as 6905ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 25 mm bore puts 61905 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 11700 r/min the grease limiting speed for 61905 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61905 at 7.8 kN dynamic (C) and 4.55 kN static (C0), 0.34 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 42 g, 61905 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 25×42×9 mm envelope of 61905 gives a D/d ratio of 1.68 and 8.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 7.8/4.55 kN load ratings, 0.34 kN fatigue load limit Cu NTN lists the grease limiting speed at 11700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 42 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6905ZZ on the 25×42×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61905 in a rated drive.",
      "Order the C3 internal-clearance version (61905 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61905 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61905-ZZ-NTN bearing?",
        "a": "A 61905-ZZ-NTN deep-groove ball bearing has a 25 mm bore, 42 mm outer diameter and 9 mm width (0.984 × 1.654 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 61905-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 61900 compare with other series at the same 25 mm bore?",
        "a": "619 is a thin section one step above 618: 42×9 mm with an 8.5 mm radial section at 25 mm bore; a 6205 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "What is the NTN suffix for a sealed 61905?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6905ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 25×42×9 mm ISO 15 envelope."
      },
      {
        "q": "Is 6905ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61905-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61905-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61905-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×42×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61905-zz",
      "6905zz",
      "61905-ZZ",
      "6905ZZ",
      "61905-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "16005-NTN",
    "brand": "NTN",
    "manufacturer_designation": "16005",
    "series": "16000-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 47,
    "B_mm": 8,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 9.25,
    "static_load_kN": 5.1,
    "fatigue_load_limit_kN": 0.4,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "weight_g": 60,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 16000-series (the narrow extra-light section of ISO 15) the last two digits encode the bore: 16005 carries bore code 05 = 25 mm. Outside diameter 47 mm and width 8 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 25 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "electric motors",
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "At a 25 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 16005-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "Because the 160xx narrow section shares the 47 mm OD of the 6005 at 25 mm bore but is only 8 mm wide, a housing machined for the wider bearing needs a spacer or relocated circlip — never assume width interchangeability.",
      "The open 16005-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 25×47×8 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 16005-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 47 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 16005-NTN.",
      "The housing bore for the 47 mm OD should be round within IT7; an oval bore pinches the outer ring of 16005-NTN and shows up later as two-point loaded raceway wear.",
      "The open 16005 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 25 mm bore puts 16005 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 16005 at 15000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 16005 at 9.25 kN dynamic (C) and 5.1 kN static (C0), 0.4 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 60 g, 16005 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 25×47×8 mm envelope of 16005 gives a D/d ratio of 1.88 and 11.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 9.25/5.1 kN load ratings, 0.4 kN fatigue load limit Cu NTN lists the grease limiting speed at 15000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 60 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 16005 on the 25×47×8 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 16005 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 16005-NTN bearing?",
        "a": "A 16005-NTN deep-groove ball bearing has a 25 mm bore, 47 mm outer diameter and 8 mm width (0.984 × 1.85 × 0.315 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 16005 bore code work?",
        "a": "The last two digits of 16005 are bore code 05, giving 05 × 5 = 25 mm bore. The 47 mm outside diameter and 8 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does no suffix on 16005 mean?",
        "a": "A bare 16005 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "What is the NTN order number for an open 16005?",
        "a": "NTN lists the open 16005 under the bare designation 16005; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 25 mm bore envelope."
      },
      {
        "q": "Is 16005 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "16005",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×47×8 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "16005",
      "16005-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6205-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6205",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 52,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 15.5,
    "static_load_kN": 7.85,
    "fatigue_load_limit_kN": 0.55,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "weight_g": 128,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6205 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 05 by five gives the 25 mm bore; the 52 mm outside diameter and 15 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 25 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "At a 25 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6205-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "At 25 mm bore the 62xx light series is the workhorse section; its 52×15 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "The open 6205-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 25×52×15 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 6200-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6205 units.",
      "Measure the shaft, do not trust the drawing: a 25 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6205-NTN.",
      "A 25 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "The open 6205 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 25 mm bore puts 6205 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 6205 at 13000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "At 15.5 kN dynamic load rating (C) and 7.85 kN static (C0), 0.55 kN fatigue load limit Cu, 6205 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 128 g, 6205 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 25×52×15 mm envelope of 6205 gives a D/d ratio of 2.08 and 13.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 15.5/7.85 kN load ratings, 0.55 kN fatigue load limit Cu NTN lists the grease limiting speed at 13000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 128 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6205 on the 25×52×15 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6205 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Standard catalogue stock of 6205 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6205-NTN bearing?",
        "a": "A 6205-NTN deep-groove ball bearing has a 25 mm bore, 52 mm outer diameter and 15 mm width (0.984 × 2.047 × 0.591 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6200 compare with other series at the same 25 mm bore?",
        "a": "The '2' is the light diameter series: 52×15 mm with a 13.5 mm radial section at 25 mm bore. A 6305 on the same bore is larger and higher-rated; a 6005 is smaller and lower-rated."
      },
      {
        "q": "Are 6205 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6205 uses the same ISO 15 envelope (25×52×15 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 6205?",
        "a": "NTN lists the open 6205 under the bare designation 6205; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 25 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6205?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6205-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6205-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6205-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6205",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6205",
      "6205-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6205-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6205LLU",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 52,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 15.5,
    "static_load_kN": 7.85,
    "fatigue_load_limit_kN": 0.55,
    "limiting_speed_rpm": 8900,
    "max_rpm": 8900,
    "weight_g": 128,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6205 carries bore code 05 = 25 mm. Outside diameter 52 mm and width 15 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 25 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6205LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "At a 25 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6205-2RS-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "At 25 mm bore the 62xx light series is the workhorse section; its 52×15 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "Contact seals add drag and heat: 6205-2RS-NTN runs slower and cooler-limited than the open 6205; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 6205-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "A 25 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 52 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6205-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6205LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 25 mm bore puts 6205 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8900 r/min the grease limiting speed for 6205 covers most general-purpose industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "At 15.5 kN dynamic load rating (C) and 7.85 kN static (C0), 0.55 kN fatigue load limit Cu, 6205 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 128 g, 6205 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 25×52×15 mm envelope of 6205 gives a D/d ratio of 2.08 and 13.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 15.5/7.85 kN load ratings, 0.55 kN fatigue load limit Cu NTN lists the grease limiting speed at 8900 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 128 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6205LLU on the 25×52×15 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6205 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6205 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6205-2RS-NTN bearing?",
        "a": "A 6205-2RS-NTN deep-groove ball bearing has a 25 mm bore, 52 mm outer diameter and 15 mm width (0.984 × 2.047 × 0.591 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What lubrication does 6205-2RS-NTN need?",
        "a": "6205-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6205 with a housing grease fitting instead."
      },
      {
        "q": "How does the 6205 bore code work?",
        "a": "The last two digits of 6205 are bore code 05, giving 05 × 5 = 25 mm bore. The 52 mm outside diameter and 15 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6205?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6205LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 25×52×15 mm ISO 15 envelope."
      },
      {
        "q": "Is 6205LLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6205-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6205-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6205-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6205",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6205-llu",
      "6205llu",
      "6205-2RS",
      "6205-2rs",
      "6205LLU",
      "6205-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6205-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6205LLB",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 52,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 15.5,
    "static_load_kN": 7.85,
    "fatigue_load_limit_kN": 0.55,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "weight_g": 128,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6205 carries bore code 05 = 25 mm. Outside diameter 52 mm and width 15 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 25 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6205LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At a 25 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6205-RSR-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 62xx light series is the default general-purpose section at 25 mm bore; before upgrading to a 6305 for extra capacity, confirm the housing accepts a 52 mm OD and 15 mm width — it is not a drop-in swap.",
      "RSR low-friction seals on 6205-RSR-NTN run faster than contact-seal 6205-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6205-2RS instead.",
      "The non-contact lip of 6205-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 25 mm bore position before relying on it as sealed-for-life.",
      "Shaft and housing fillets must clear the bearing chamfer so the 15 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Vibration during standstill brinells the raceways of a 25 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues this low-friction non-contact seal as 6205LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 25 mm bore puts 6205 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 11000 r/min the grease limiting speed for 6205 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 15.5 kN dynamic load rating (C) and 7.85 kN static (C0), 0.55 kN fatigue load limit Cu, 6205 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 128 g, 6205 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 25×52×15 mm envelope of 6205 gives a D/d ratio of 2.08 and 13.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 15.5/7.85 kN load ratings, 0.55 kN fatigue load limit Cu NTN lists the grease limiting speed at 11000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 128 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6205LLB on the 25×52×15 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6205 in a rated drive.",
      "Order the C3 internal-clearance version (6205 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6205-RSR-NTN bearing?",
        "a": "A 6205-RSR-NTN deep-groove ball bearing has a 25 mm bore, 52 mm outer diameter and 15 mm width (0.984 × 2.047 × 0.591 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What internal clearance does 6205-RSR-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6205-RSR-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6205 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6205-RSR-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 25 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 6205?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6205LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 25×52×15 mm ISO 15 envelope."
      },
      {
        "q": "Is 6205LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6205-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6205-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6205-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6205",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6205-llb",
      "6205llb",
      "6205-RSR",
      "6205-rsr",
      "6205LLB",
      "6205-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6205-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6205ZZ",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 52,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 15.5,
    "static_load_kN": 7.85,
    "fatigue_load_limit_kN": 0.55,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "weight_g": 128,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6205 carries bore code 05 = 25 mm. Outside diameter 52 mm and width 15 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 25 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6205ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers",
      "electric motors"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Sizes around 25 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6205-ZZ-NTN.",
      "The 62xx light series is the default general-purpose section at 25 mm bore; before upgrading to a 6305 for extra capacity, confirm the housing accepts a 52 mm OD and 15 mm width — it is not a drop-in swap.",
      "Do not wash 6205-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6205-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Shaft and housing fillets must clear the bearing chamfer so the 15 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Never mix components between two 6205-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the shielded version as 6205ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 25 mm bore puts 6205 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 11000 r/min the grease limiting speed for 6205 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 15.5 kN dynamic load rating (C) and 7.85 kN static (C0), 0.55 kN fatigue load limit Cu, 6205 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 128 g, 6205 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 25×52×15 mm envelope of 6205 gives a D/d ratio of 2.08 and 13.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 15.5/7.85 kN load ratings, 0.55 kN fatigue load limit Cu NTN lists the grease limiting speed at 11000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 128 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6205ZZ on the 25×52×15 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6205 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Standard catalogue stock of 6205 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6205-ZZ-NTN bearing?",
        "a": "A 6205-ZZ-NTN deep-groove ball bearing has a 25 mm bore, 52 mm outer diameter and 15 mm width (0.984 × 2.047 × 0.591 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "Are 6205 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6205 uses the same ISO 15 envelope (25×52×15 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 6205-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6205-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6205 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 6205?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6205ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 25×52×15 mm ISO 15 envelope."
      },
      {
        "q": "Is 6205ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6205-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6205-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6205-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6205-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6205",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×52×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6205-zz",
      "6205zz",
      "6205-ZZ",
      "6205ZZ",
      "6205-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6305-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6305",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 62,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 23.5,
    "static_load_kN": 10.9,
    "fatigue_load_limit_kN": 0.85,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 232,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6305 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 05 by five gives the 25 mm bore; the 62 mm outside diameter and 17 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 25 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "A 25 mm shaft for 6305 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 63xx medium section at 25 mm bore gains dynamic rating through larger rolling elements on a 62 mm OD; the penalty is mass and a lower limiting speed than the 6205 — do not specify it for speed-critical shafts.",
      "The open 6305-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 25×62×17 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6305-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Vibration during standstill brinells the raceways of a 25 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6305-NTN-C3. No clearance suffix means normal CN clearance.",
      "The open 6305 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 25 mm bore puts 6305 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 6305 at 12000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "At 23.5 kN dynamic load rating (C) and 10.9 kN static (C0), 0.85 kN fatigue load limit Cu, 6305 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 232 g, 6305 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 25×62×17 mm envelope of 6305 gives a D/d ratio of 2.48 and 18.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 23.5/10.9 kN load ratings, 0.85 kN fatigue load limit Cu NTN lists the grease limiting speed at 12000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 232 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6305 on the 25×62×17 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6305 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6305-NTN bearing?",
        "a": "A 6305-NTN deep-groove ball bearing has a 25 mm bore, 62 mm outer diameter and 17 mm width (0.984 × 2.441 × 0.669 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6305 bore code work?",
        "a": "The last two digits of 6305 are bore code 05, giving 05 × 5 = 25 mm bore. The 62 mm outside diameter and 17 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does no suffix on 6305 mean?",
        "a": "A bare 6305 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "What is the NTN order number for an open 6305?",
        "a": "NTN lists the open 6305 under the bare designation 6305; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 25 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6305?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6305-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6305-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6305-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6305",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "305",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "305-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6305",
      "6305-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6305-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6305LLU",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 62,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 23.5,
    "static_load_kN": 10.9,
    "fatigue_load_limit_kN": 0.85,
    "limiting_speed_rpm": 8100,
    "max_rpm": 8100,
    "weight_g": 232,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6305-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 05 by five gives the 25 mm bore; the 62 mm outside diameter and 17 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 25 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6305LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "fans and blowers",
      "electric motors",
      "centrifugal pumps",
      "small gearboxes"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At a 25 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6305-2RS-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 63xx medium series gains rating at 25 mm bore through a 62 mm OD and 17 mm width; the heavier rolling elements also trade away some speed versus a 6205.",
      "Heat is the enemy of the sealed 6305-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 6305-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 62 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6305-2RS-NTN.",
      "Measure the shaft, do not trust the drawing: a 25 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6305-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6305LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 25 mm bore puts 6305 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8100 r/min the grease limiting speed for 6305 covers most general-purpose industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "At 23.5 kN dynamic load rating (C) and 10.9 kN static (C0), 0.85 kN fatigue load limit Cu, 6305 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 232 g, 6305 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 25×62×17 mm envelope of 6305 gives a D/d ratio of 2.48 and 18.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 23.5/10.9 kN load ratings, 0.85 kN fatigue load limit Cu NTN lists the grease limiting speed at 8100 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 232 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6305LLU on the 25×62×17 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6305 in a rated drive.",
      "Order the C3 internal-clearance version (6305 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6305-2RS-NTN bearing?",
        "a": "A 6305-2RS-NTN deep-groove ball bearing has a 25 mm bore, 62 mm outer diameter and 17 mm width (0.984 × 2.441 × 0.669 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 6305 bore code work?",
        "a": "The last two digits of 6305 are bore code 05, giving 05 × 5 = 25 mm bore. The 62 mm outside diameter and 17 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the 2RS suffix on 6305-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "What is the NTN suffix for a sealed 6305?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6305LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 25×62×17 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6305LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6305-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6305-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6305-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6305",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "305",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "305-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6305-llu",
      "6305llu",
      "6305-2RS",
      "6305-2rs",
      "6305LLU",
      "6305-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6305-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6305LLB",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 62,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 23.5,
    "static_load_kN": 10.9,
    "fatigue_load_limit_kN": 0.85,
    "limiting_speed_rpm": 9700,
    "max_rpm": 9700,
    "weight_g": 232,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6305 carries bore code 05 = 25 mm. Outside diameter 62 mm and width 17 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 25 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6305LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers",
      "electric motors"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "A 25 mm shaft for 6305 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 63xx medium series gains rating at 25 mm bore through a 62 mm OD and 17 mm width; the heavier rolling elements also trade away some speed versus a 6205.",
      "RSR low-friction seals on 6305-RSR-NTN run faster than contact-seal 6305-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6305-2RS instead.",
      "The non-contact lip of 6305-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 25 mm bore position before relying on it as sealed-for-life.",
      "Shaft and housing fillets must clear the bearing chamfer so the 17 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Never mix components between two 6305-RSR-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues this low-friction non-contact seal as 6305LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 25 mm bore puts 6305 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 9700 r/min the grease limiting speed for 6305 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 23.5 kN dynamic load rating (C) and 10.9 kN static (C0), 0.85 kN fatigue load limit Cu, 6305 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 232 g, 6305 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 25×62×17 mm envelope of 6305 gives a D/d ratio of 2.48 and 18.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 23.5/10.9 kN load ratings, 0.85 kN fatigue load limit Cu NTN lists the grease limiting speed at 9700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 232 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6305LLB on the 25×62×17 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6305 in a rated drive.",
      "Order the C3 internal-clearance version (6305 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6305-RSR-NTN bearing?",
        "a": "A 6305-RSR-NTN deep-groove ball bearing has a 25 mm bore, 62 mm outer diameter and 17 mm width (0.984 × 2.441 × 0.669 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "Are 6305 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6305 uses the same ISO 15 envelope (25×62×17 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 6305-RSR-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6305-RSR-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6305 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 6305?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6305LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 25×62×17 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6305 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6305LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6305-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6305-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6305-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6305",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "305",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "305-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6305-llb",
      "6305llb",
      "6305-RSR",
      "6305-rsr",
      "6305LLB",
      "6305-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6305-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6305ZZ",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 62,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 23.5,
    "static_load_kN": 10.9,
    "fatigue_load_limit_kN": 0.85,
    "limiting_speed_rpm": 9700,
    "max_rpm": 9700,
    "weight_g": 232,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6305-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 05 by five gives the 25 mm bore; the 62 mm outside diameter and 17 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 25 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6305ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "At a 25 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6305-ZZ-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 63xx medium section at 25 mm bore gains dynamic rating through larger rolling elements on a 62 mm OD; the penalty is mass and a lower limiting speed than the 6205 — do not specify it for speed-critical shafts.",
      "ZZ shields are non-contact: 6305-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6305-2RS for that.",
      "Do not wash 6305-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Measure the shaft, do not trust the drawing: a 25 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6305-ZZ-NTN.",
      "Do not quieten a noisy bearing by preloading it: the 6300-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues the shielded version as 6305ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 25 mm bore puts 6305 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 9700 r/min the grease limiting speed for 6305 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 23.5 kN dynamic load rating (C) and 10.9 kN static (C0), 0.85 kN fatigue load limit Cu, 6305 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 232 g, 6305 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 25×62×17 mm envelope of 6305 gives a D/d ratio of 2.48 and 18.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 23.5/10.9 kN load ratings, 0.85 kN fatigue load limit Cu NTN lists the grease limiting speed at 9700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 232 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6305ZZ on the 25×62×17 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6305 in a rated drive.",
      "Standard catalogue stock of 6305 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6305 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6305-ZZ-NTN bearing?",
        "a": "A 6305-ZZ-NTN deep-groove ball bearing has a 25 mm bore, 62 mm outer diameter and 17 mm width (0.984 × 2.441 × 0.669 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 6305-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 6300 compare with other series at the same 25 mm bore?",
        "a": "The '3' is the medium diameter series: 62×17 mm, 18.5 mm radial section at 25 mm bore, carrying more load than a 6205 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "What is the NTN suffix for a sealed 6305?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6305ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 25×62×17 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6305 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6305ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6305-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6305-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6305-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6305-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6305",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "305",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "305-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×62×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6305-zz",
      "6305zz",
      "6305-ZZ",
      "6305ZZ",
      "6305-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6405-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6405",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 80,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 38.5,
    "static_load_kN": 17.5,
    "fatigue_load_limit_kN": 1.36,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "weight_g": 530,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6405 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the heavy 64xx section (diameter series 4 of ISO 15), multiplying bore code 05 by five gives the 25 mm bore; the 80 mm outside diameter and 21 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 25 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "electric motors",
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "A 25 mm shaft for 6405 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 64xx heavy section at 25 mm bore (80 mm OD) is built for high-load, lower-speed duty; specifying it in a high-rpm motor gives excess heat and short grease life — use 62/63 there.",
      "The open 6405-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 25×80×21 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6405-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Vibration during standstill brinells the raceways of a 25 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Never mix components between two 6405-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "The open 6405 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 25 mm bore puts 6405 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 10000 r/min the grease limiting speed for 6405 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6405 at 38.5 kN dynamic (C) and 17.5 kN static (C0), 1.36 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 530 g, 6405 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 25×80×21 mm envelope of 6405 gives a D/d ratio of 3.20 and 27.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 38.5/17.5 kN load ratings, 1.36 kN fatigue load limit Cu NTN lists the grease limiting speed at 10000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 530 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6405 on the 25×80×21 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6405 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6405 is listed.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6405-NTN bearing?",
        "a": "A 6405-NTN deep-groove ball bearing has a 25 mm bore, 80 mm outer diameter and 21 mm width (0.984 × 3.15 × 0.827 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 6405 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6405 uses the same ISO 15 envelope (25×80×21 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 6405-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6405-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6405 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 6405?",
        "a": "NTN lists the open 6405 under the bare designation 6405; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 25 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6405?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6405-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6405-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 25×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6405",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6405",
      "6405-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6405-ZZ",
    "brand": "NTN",
    "manufacturer_designation": "6405ZZ",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 25,
    "D_mm": 80,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 38.5,
    "static_load_kN": 17.5,
    "fatigue_load_limit_kN": 1.36,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "weight_g": 530,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6405-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the heavy 64xx section (diameter series 4 of ISO 15), multiplying bore code 05 by five gives the 25 mm bore; the 80 mm outside diameter and 21 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 25 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6405ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "fans and blowers",
      "electric motors",
      "centrifugal pumps",
      "small gearboxes"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Sizes around 25 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6405-ZZ.",
      "The 64xx heavy section at 25 mm bore exists for high radial load at moderate rpm; its 80 mm OD and 21 mm width demand a larger housing, and grease life at motor speeds is short — treat it as a low-speed, high-load choice.",
      "ZZ shields are non-contact: 6405-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6405-2RS for that.",
      "Shielded 6405-ZZ units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 21 mm-wide ring of 6405-ZZ drags the lip and overheats it.",
      "The housing bore for the 80 mm OD should be round within IT7; an oval bore pinches the outer ring of 6405-ZZ and shows up later as two-point loaded raceway wear.",
      "NTN catalogues the shielded version as 6405ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 25 mm bore puts 6405 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 10000 r/min the grease limiting speed for 6405 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6405 at 38.5 kN dynamic (C) and 17.5 kN static (C0), 1.36 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 530 g, 6405 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 25×80×21 mm envelope of 6405 gives a D/d ratio of 3.20 and 27.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 38.5/17.5 kN load ratings, 1.36 kN fatigue load limit Cu NTN lists the grease limiting speed at 10000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 530 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6405ZZ on the 25×80×21 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6405 in a rated drive.",
      "Standard catalogue stock of 6405 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6405-ZZ bearing?",
        "a": "A 6405-ZZ deep-groove ball bearing has a 25 mm bore, 80 mm outer diameter and 21 mm width (0.984 × 3.15 × 0.827 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 6400 compare with other series at the same 25 mm bore?",
        "a": "The '4' is the heavy diameter series: 80×21 mm, 27.5 mm radial section at 25 mm bore — the highest-capacity single-row 6xx option here, aimed at lower-speed, high-load shafts."
      },
      {
        "q": "Are 6405 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6405 uses the same ISO 15 envelope (25×80×21 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6405?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6405ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 25×80×21 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6405ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6405-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 25×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6405-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 25×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6405",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 25×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6405-zz",
      "6405zz",
      "6405-ZZ",
      "6405ZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61806-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6806JR",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 42,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.2,
    "static_load_kN": 3.65,
    "fatigue_load_limit_kN": 0.24,
    "limiting_speed_rpm": 15000,
    "max_rpm": 15000,
    "weight_g": 26,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61806 carries bore code 06 = 30 mm. Outside diameter 42 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 30 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At a 30 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61806-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 618xx thin section at 30 mm bore has only a 6.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6206.",
      "The open 61806-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 30×42×7 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 61806-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Shaft and housing fillets must clear the bearing chamfer so the 7 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Vibration during standstill brinells the raceways of a 30 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "The open 61806 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 30 mm bore puts 61806 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61806 at 15000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 61806 at 5.2 kN dynamic (C) and 3.65 kN static (C0), 0.24 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 26 g, 61806 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 30×42×7 mm envelope of 61806 gives a D/d ratio of 1.40 and 6.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 5.2/3.65 kN load ratings, 0.24 kN fatigue load limit Cu NTN lists the grease limiting speed at 15000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 26 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6806JR on the 30×42×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61806 in a rated drive.",
      "Standard catalogue stock of 61806 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61806-NTN bearing?",
        "a": "A 61806-NTN deep-groove ball bearing has a 30 mm bore, 42 mm outer diameter and 7 mm width (1.181 × 1.654 × 0.276 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 61806 bore code work?",
        "a": "The last two digits of 61806 are bore code 06, giving 06 × 5 = 30 mm bore. The 42 mm outside diameter and 7 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does no suffix on 61806 mean?",
        "a": "A bare 61806 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "What is the NTN order number for an open 61806?",
        "a": "NTN lists the open 61806 under the bare designation 6806JR; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 30 mm bore envelope."
      },
      {
        "q": "Does NTN offer 61806 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6806JR is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61806-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61806-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6806jr",
      "61806",
      "6806JR",
      "61806-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61806-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6806JRLLU",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 42,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.2,
    "static_load_kN": 3.65,
    "fatigue_load_limit_kN": 0.24,
    "limiting_speed_rpm": 8800,
    "max_rpm": 8800,
    "weight_g": 26,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61806-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 06 by five gives the 30 mm bore; the 42 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 30 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6806JRLLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Sizes around 30 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 61806-2RS-NTN.",
      "Only 6.0 mm of radial section separates bore and OD on the 618xx series at 30 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6206.",
      "Contact seals add drag and heat: 61806-2RS-NTN runs slower and cooler-limited than the open 61806; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 61806-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61800-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Never mix components between two 61806-2RS-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the contact-sealed version as 6806JRLLU (suffix RLLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 30 mm bore puts 61806 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8800 r/min the grease limiting speed for 61806 covers most general-purpose industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 61806 at 5.2 kN dynamic (C) and 3.65 kN static (C0), 0.24 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 26 g, 61806 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 30×42×7 mm envelope of 61806 gives a D/d ratio of 1.40 and 6.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 5.2/3.65 kN load ratings, 0.24 kN fatigue load limit Cu NTN lists the grease limiting speed at 8800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 26 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6806JRLLU on the 30×42×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61806 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Order the C3 internal-clearance version (61806 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61806-2RS-NTN bearing?",
        "a": "A 61806-2RS-NTN deep-groove ball bearing has a 30 mm bore, 42 mm outer diameter and 7 mm width (1.181 × 1.654 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 61800 compare with other series at the same 30 mm bore?",
        "a": "618 is an extra-thin section: 42×7 mm, only 6.0 mm radial section at 30 mm bore, far smaller than a 6206, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "Are 61806 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61806 uses the same ISO 15 envelope (30×42×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61806?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6806JRLLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 30×42×7 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61806 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6806JRLLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61806-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61806-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61806-llu",
      "6806jrllu",
      "6806llu",
      "61806-2RS",
      "61806-2rs",
      "6806JRLLU",
      "61806-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61806-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6806JRLLB",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 42,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.2,
    "static_load_kN": 3.65,
    "fatigue_load_limit_kN": 0.24,
    "limiting_speed_rpm": 10500,
    "max_rpm": 10500,
    "weight_g": 26,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61806-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 06 by five gives the 30 mm bore; the 42 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 30 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6806JRLLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Sizes around 30 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 61806-RSR-NTN.",
      "Only 6.0 mm of radial section separates bore and OD on the 618xx series at 30 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6206.",
      "RSR low-friction seals on 61806-RSR-NTN run faster than contact-seal 61806-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61806-2RS instead.",
      "The low-drag lip of 61806-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61806-RSR-NTN-C3. No clearance suffix means normal CN clearance.",
      "Never mix components between two 61806-RSR-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues this low-friction non-contact seal as 6806JRLLB (suffix RLLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 30 mm bore puts 61806 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 10500 r/min the grease limiting speed for 61806 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61806 at 5.2 kN dynamic (C) and 3.65 kN static (C0), 0.24 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 26 g, 61806 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 30×42×7 mm envelope of 61806 gives a D/d ratio of 1.40 and 6.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 5.2/3.65 kN load ratings, 0.24 kN fatigue load limit Cu NTN lists the grease limiting speed at 10500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 26 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6806JRLLB on the 30×42×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61806 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61806 is listed.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61806-RSR-NTN bearing?",
        "a": "A 61806-RSR-NTN deep-groove ball bearing has a 30 mm bore, 42 mm outer diameter and 7 mm width (1.181 × 1.654 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How should 61806-RSR-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 30 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 61806-RSR-NTN need?",
        "a": "61806-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61806 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 61806?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6806JRLLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 30×42×7 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6806JRLLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61806-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61806-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61806-llb",
      "6806jrllb",
      "6806llb",
      "61806-RSR",
      "61806-rsr",
      "6806JRLLB",
      "61806-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61806-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6806JRZZ",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 42,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.2,
    "static_load_kN": 3.65,
    "fatigue_load_limit_kN": 0.24,
    "limiting_speed_rpm": 10500,
    "max_rpm": 10500,
    "weight_g": 26,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61806 carries bore code 06 = 30 mm. Outside diameter 42 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 30 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6806JRZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "A 30 mm shaft for 61806 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 618xx thin section at 30 mm bore has only a 6.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6206.",
      "Do not wash 61806-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 61806-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Never mix components between two 61806-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61806-ZZ-NTN-C3. No clearance suffix means normal CN clearance.",
      "NTN catalogues the shielded version as 6806JRZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 30 mm bore puts 61806 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 10500 r/min the grease limiting speed for 61806 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61806 at 5.2 kN dynamic (C) and 3.65 kN static (C0), 0.24 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 26 g, 61806 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 30×42×7 mm envelope of 61806 gives a D/d ratio of 1.40 and 6.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 5.2/3.65 kN load ratings, 0.24 kN fatigue load limit Cu NTN lists the grease limiting speed at 10500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 26 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6806JRZZ on the 30×42×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61806 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Standard catalogue stock of 61806 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61806-ZZ-NTN bearing?",
        "a": "A 61806-ZZ-NTN deep-groove ball bearing has a 30 mm bore, 42 mm outer diameter and 7 mm width (1.181 × 1.654 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "Are 61806 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61806 uses the same ISO 15 envelope (30×42×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 61806-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61806-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61806 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 61806?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6806JRZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 30×42×7 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6806JRZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61806-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61806-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61806-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×42×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61806-zz",
      "6806jrzz",
      "6806zz",
      "61806-ZZ",
      "6806JRZZ",
      "61806-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61906-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6906",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 47,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 8,
    "static_load_kN": 5,
    "fatigue_load_limit_kN": 0.36,
    "limiting_speed_rpm": 14000,
    "max_rpm": 14000,
    "weight_g": 48,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61906 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 06 by five gives the 30 mm bore; the 47 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 30 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Sizes around 30 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 61906-NTN.",
      "The 619xx thin section (8.5 mm section height at 30 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "The open 61906-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 30×47×9 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 61900-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61906 units.",
      "Measure the shaft, do not trust the drawing: a 30 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61906-NTN.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 47 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61906-NTN.",
      "The open 61906 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 30 mm bore puts 61906 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61906 at 14000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 61906 at 8 kN dynamic (C) and 5 kN static (C0), 0.36 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 48 g, 61906 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 30×47×9 mm envelope of 61906 gives a D/d ratio of 1.57 and 8.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 8/5 kN load ratings, 0.36 kN fatigue load limit Cu NTN lists the grease limiting speed at 14000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 48 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6906 on the 30×47×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61906 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Order the C3 internal-clearance version (61906 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61906-NTN bearing?",
        "a": "A 61906-NTN deep-groove ball bearing has a 30 mm bore, 47 mm outer diameter and 9 mm width (1.181 × 1.85 × 0.354 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 61906 bore code work?",
        "a": "The last two digits of 61906 are bore code 06, giving 06 × 5 = 30 mm bore. The 47 mm outside diameter and 9 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does no suffix on 61906 mean?",
        "a": "A bare 61906 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "What is the NTN order number for an open 61906?",
        "a": "NTN lists the open 61906 under the bare designation 6906; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 30 mm bore envelope."
      },
      {
        "q": "Is 6906 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61906-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61906-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61906",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6906",
      "61906",
      "61906-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61906-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6906LLU",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 47,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 8,
    "static_load_kN": 5,
    "fatigue_load_limit_kN": 0.36,
    "limiting_speed_rpm": 8400,
    "max_rpm": 8400,
    "weight_g": 48,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61906 carries bore code 06 = 30 mm. Outside diameter 47 mm and width 9 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 30 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6906LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "At a 30 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61906-2RS-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 619xx thin section (8.5 mm section height at 30 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "Contact seals add drag and heat: 61906-2RS-NTN runs slower and cooler-limited than the open 61906; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 61906-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "Shaft and housing fillets must clear the bearing chamfer so the 9 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues the contact-sealed version as 6906LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 30 mm bore puts 61906 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8400 r/min the grease limiting speed for 61906 covers most general-purpose industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 61906 at 8 kN dynamic (C) and 5 kN static (C0), 0.36 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 48 g, 61906 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 30×47×9 mm envelope of 61906 gives a D/d ratio of 1.57 and 8.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 8/5 kN load ratings, 0.36 kN fatigue load limit Cu NTN lists the grease limiting speed at 8400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 48 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6906LLU on the 30×47×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61906 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61906-2RS-NTN bearing?",
        "a": "A 61906-2RS-NTN deep-groove ball bearing has a 30 mm bore, 47 mm outer diameter and 9 mm width (1.181 × 1.85 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 61900 compare with other series at the same 30 mm bore?",
        "a": "619 is a thin section one step above 618: 47×9 mm with an 8.5 mm radial section at 30 mm bore; a 6206 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "Are 61906 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61906 uses the same ISO 15 envelope (30×47×9 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61906?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6906LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 30×47×9 mm ISO 15 envelope."
      },
      {
        "q": "Is 6906LLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61906-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61906-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61906",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61906-llu",
      "6906llu",
      "61906-2RS",
      "61906-2rs",
      "6906LLU",
      "61906-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61906-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6906LLB",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 47,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 8,
    "static_load_kN": 5,
    "fatigue_load_limit_kN": 0.36,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "weight_g": 48,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61906-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 06 by five gives the 30 mm bore; the 47 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 30 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6906LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "At a 30 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61906-RSR-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 619xx thin section at 30 mm bore (8.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "The low-drag lip of 61906-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 61906-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 30 mm bore position before relying on it as sealed-for-life.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 47 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61906-RSR-NTN.",
      "The housing bore for the 47 mm OD should be round within IT7; an oval bore pinches the outer ring of 61906-RSR-NTN and shows up later as two-point loaded raceway wear.",
      "NTN catalogues this low-friction non-contact seal as 6906LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 30 mm bore puts 61906 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 10000 r/min the grease limiting speed for 61906 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61906 at 8 kN dynamic (C) and 5 kN static (C0), 0.36 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 48 g, 61906 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 30×47×9 mm envelope of 61906 gives a D/d ratio of 1.57 and 8.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 8/5 kN load ratings, 0.36 kN fatigue load limit Cu NTN lists the grease limiting speed at 10000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 48 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6906LLB on the 30×47×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61906 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61906 is listed.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61906-RSR-NTN bearing?",
        "a": "A 61906-RSR-NTN deep-groove ball bearing has a 30 mm bore, 47 mm outer diameter and 9 mm width (1.181 × 1.85 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What internal clearance does 61906-RSR-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61906-RSR-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61906 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61906-RSR-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 30 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 61906?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6906LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 30×47×9 mm ISO 15 envelope."
      },
      {
        "q": "Is 6906LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61906-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61906-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61906",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61906-llb",
      "6906llb",
      "61906-RSR",
      "61906-rsr",
      "6906LLB",
      "61906-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61906-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6906ZZ",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 47,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 8,
    "static_load_kN": 5,
    "fatigue_load_limit_kN": 0.36,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "weight_g": 48,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61906-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 06 by five gives the 30 mm bore; the 47 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 30 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6906ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "At a 30 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61906-ZZ-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 619xx thin section (8.5 mm section height at 30 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "ZZ shields are non-contact: 61906-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61906-2RS for that.",
      "Do not wash 61906-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Never mix components between two 61906-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Measure the shaft, do not trust the drawing: a 30 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61906-ZZ-NTN.",
      "NTN catalogues the shielded version as 6906ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 30 mm bore puts 61906 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 10000 r/min the grease limiting speed for 61906 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61906 at 8 kN dynamic (C) and 5 kN static (C0), 0.36 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 48 g, 61906 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 30×47×9 mm envelope of 61906 gives a D/d ratio of 1.57 and 8.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 8/5 kN load ratings, 0.36 kN fatigue load limit Cu NTN lists the grease limiting speed at 10000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 48 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6906ZZ on the 30×47×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61906 in a rated drive.",
      "Order the C3 internal-clearance version (61906 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Standard catalogue stock of 61906 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61906-ZZ-NTN bearing?",
        "a": "A 61906-ZZ-NTN deep-groove ball bearing has a 30 mm bore, 47 mm outer diameter and 9 mm width (1.181 × 1.85 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 61906-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 61900 compare with other series at the same 30 mm bore?",
        "a": "619 is a thin section one step above 618: 47×9 mm with an 8.5 mm radial section at 30 mm bore; a 6206 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "What is the NTN suffix for a sealed 61906?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6906ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 30×47×9 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6906ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61906-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61906-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61906-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61906",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×47×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61906-zz",
      "6906zz",
      "61906-ZZ",
      "6906ZZ",
      "61906-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "16006-NTN",
    "brand": "NTN",
    "manufacturer_designation": "16006",
    "series": "16000-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 55,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 12.5,
    "static_load_kN": 7.35,
    "fatigue_load_limit_kN": 0.57,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "weight_g": 91,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 16000-series (the narrow extra-light section of ISO 15) the last two digits encode the bore: 16006 carries bore code 06 = 30 mm. Outside diameter 55 mm and width 9 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 30 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Sizes around 30 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 16006-NTN.",
      "Because the 160xx narrow section shares the 55 mm OD of the 6006 at 30 mm bore but is only 9 mm wide, a housing machined for the wider bearing needs a spacer or relocated circlip — never assume width interchangeability.",
      "Storage matters for open bearings: 16006-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 16000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 16006 units.",
      "A 30 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Shaft and housing fillets must clear the bearing chamfer so the 9 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "The open 16006 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 30 mm bore puts 16006 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 16006 at 13000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 16006 at 12.5 kN dynamic (C) and 7.35 kN static (C0), 0.57 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 91 g, 16006 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 30×55×9 mm envelope of 16006 gives a D/d ratio of 1.83 and 12.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 12.5/7.35 kN load ratings, 0.57 kN fatigue load limit Cu NTN lists the grease limiting speed at 13000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 91 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 16006 on the 30×55×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 16006 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 16006 is listed.",
      "Standard catalogue stock of 16006 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 16006-NTN bearing?",
        "a": "A 16006-NTN deep-groove ball bearing has a 30 mm bore, 55 mm outer diameter and 9 mm width (1.181 × 2.165 × 0.354 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 16006 bore code work?",
        "a": "The last two digits of 16006 are bore code 06, giving 06 × 5 = 30 mm bore. The 55 mm outside diameter and 9 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does no suffix on 16006 mean?",
        "a": "A bare 16006 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "What is the NTN order number for an open 16006?",
        "a": "NTN lists the open 16006 under the bare designation 16006; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 30 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 16006?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "16006",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×55×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "16006",
      "16006-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6206-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6206",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 62,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 21.6,
    "static_load_kN": 11.3,
    "fatigue_load_limit_kN": 0.8,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "weight_g": 199,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6206 carries bore code 06 = 30 mm. Outside diameter 62 mm and width 16 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 30 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At a 30 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6206-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 62xx light series is the default general-purpose section at 30 mm bore; before upgrading to a 6306 for extra capacity, confirm the housing accepts a 62 mm OD and 16 mm width — it is not a drop-in swap.",
      "The open 6206-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 30×62×16 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 6200-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6206 units.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6206-NTN-C3. No clearance suffix means normal CN clearance.",
      "Measure the shaft, do not trust the drawing: a 30 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6206-NTN.",
      "The open 6206 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 30 mm bore puts 6206 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 11000 r/min the grease limiting speed for 6206 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 21.6 kN dynamic load rating (C) and 11.3 kN static (C0), 0.8 kN fatigue load limit Cu, 6206 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 199 g, 6206 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 30×62×16 mm envelope of 6206 gives a D/d ratio of 2.07 and 16.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 21.6/11.3 kN load ratings, 0.8 kN fatigue load limit Cu NTN lists the grease limiting speed at 11000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 199 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6206 on the 30×62×16 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6206 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Order the C3 internal-clearance version (6206 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6206-NTN bearing?",
        "a": "A 6206-NTN deep-groove ball bearing has a 30 mm bore, 62 mm outer diameter and 16 mm width (1.181 × 2.441 × 0.63 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How should 6206-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 30 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6206-NTN need?",
        "a": "The open 6206-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "What is the NTN order number for an open 6206?",
        "a": "NTN lists the open 6206 under the bare designation 6206; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 30 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6206?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6206-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6206-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6206-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6206",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "206",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "206-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6206",
      "6206-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6206-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6206LLU",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 62,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 21.6,
    "static_load_kN": 11.3,
    "fatigue_load_limit_kN": 0.8,
    "limiting_speed_rpm": 7300,
    "max_rpm": 7300,
    "weight_g": 199,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6206-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 06 by five gives the 30 mm bore; the 62 mm outside diameter and 16 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 30 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6206LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers",
      "electric motors"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Sizes around 30 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6206-2RS-NTN.",
      "At 30 mm bore the 62xx light series is the workhorse section; its 62×16 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "Contact seals add drag and heat: 6206-2RS-NTN runs slower and cooler-limited than the open 6206; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 6206-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6200-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Shaft and housing fillets must clear the bearing chamfer so the 16 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues the contact-sealed version as 6206LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 30 mm bore puts 6206 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7300 r/min the grease limiting speed for 6206 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "At 21.6 kN dynamic load rating (C) and 11.3 kN static (C0), 0.8 kN fatigue load limit Cu, 6206 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 199 g, 6206 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 30×62×16 mm envelope of 6206 gives a D/d ratio of 2.07 and 16.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 21.6/11.3 kN load ratings, 0.8 kN fatigue load limit Cu NTN lists the grease limiting speed at 7300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 199 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6206LLU on the 30×62×16 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6206 in a rated drive.",
      "Order the C3 internal-clearance version (6206 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6206 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6206-2RS-NTN bearing?",
        "a": "A 6206-2RS-NTN deep-groove ball bearing has a 30 mm bore, 62 mm outer diameter and 16 mm width (1.181 × 2.441 × 0.63 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "Are 6206 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6206 uses the same ISO 15 envelope (30×62×16 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 6206-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6206-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6206 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 6206?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6206LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 30×62×16 mm ISO 15 envelope."
      },
      {
        "q": "Is 6206LLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6206-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6206-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6206-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6206",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "206",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "206-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6206-llu",
      "6206llu",
      "6206-2RS",
      "6206-2rs",
      "6206LLU",
      "6206-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6206-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6206LLB",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 62,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 21.6,
    "static_load_kN": 11.3,
    "fatigue_load_limit_kN": 0.8,
    "limiting_speed_rpm": 8800,
    "max_rpm": 8800,
    "weight_g": 199,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6206 carries bore code 06 = 30 mm. Outside diameter 62 mm and width 16 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 30 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6206LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Sizes around 30 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6206-RSR-NTN.",
      "The 62xx light series is the default general-purpose section at 30 mm bore; before upgrading to a 6306 for extra capacity, confirm the housing accepts a 62 mm OD and 16 mm width — it is not a drop-in swap.",
      "RSR low-friction seals on 6206-RSR-NTN run faster than contact-seal 6206-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6206-2RS instead.",
      "The non-contact lip of 6206-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 30 mm bore position before relying on it as sealed-for-life.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 62 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6206-RSR-NTN.",
      "Do not quieten a noisy bearing by preloading it: the 6200-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues this low-friction non-contact seal as 6206LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 30 mm bore puts 6206 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8800 r/min the grease limiting speed for 6206 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 21.6 kN dynamic load rating (C) and 11.3 kN static (C0), 0.8 kN fatigue load limit Cu, 6206 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 199 g, 6206 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 30×62×16 mm envelope of 6206 gives a D/d ratio of 2.07 and 16.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 21.6/11.3 kN load ratings, 0.8 kN fatigue load limit Cu NTN lists the grease limiting speed at 8800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 199 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6206LLB on the 30×62×16 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6206 in a rated drive.",
      "Order the C3 internal-clearance version (6206 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6206-RSR-NTN bearing?",
        "a": "A 6206-RSR-NTN deep-groove ball bearing has a 30 mm bore, 62 mm outer diameter and 16 mm width (1.181 × 2.441 × 0.63 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6206 bore code work?",
        "a": "The last two digits of 6206 are bore code 06, giving 06 × 5 = 30 mm bore. The 62 mm outside diameter and 16 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the RSR suffix on 6206-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "What is the NTN suffix for a sealed 6206?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6206LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 30×62×16 mm ISO 15 envelope."
      },
      {
        "q": "Is 6206LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6206-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6206-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6206-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6206",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "206",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "206-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6206-llb",
      "6206llb",
      "6206-RSR",
      "6206-rsr",
      "6206LLB",
      "6206-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6206-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6206ZZ",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 62,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 21.6,
    "static_load_kN": 11.3,
    "fatigue_load_limit_kN": 0.8,
    "limiting_speed_rpm": 8800,
    "max_rpm": 8800,
    "weight_g": 199,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6206 carries bore code 06 = 30 mm. Outside diameter 62 mm and width 16 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 30 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6206ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At a 30 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6206-ZZ-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 62xx light series is the default general-purpose section at 30 mm bore; before upgrading to a 6306 for extra capacity, confirm the housing accepts a 62 mm OD and 16 mm width — it is not a drop-in swap.",
      "Do not wash 6206-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6206-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6206-ZZ-NTN-C3. No clearance suffix means normal CN clearance.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6200-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "NTN catalogues the shielded version as 6206ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 30 mm bore puts 6206 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8800 r/min the grease limiting speed for 6206 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 21.6 kN dynamic load rating (C) and 11.3 kN static (C0), 0.8 kN fatigue load limit Cu, 6206 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 199 g, 6206 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 30×62×16 mm envelope of 6206 gives a D/d ratio of 2.07 and 16.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 21.6/11.3 kN load ratings, 0.8 kN fatigue load limit Cu NTN lists the grease limiting speed at 8800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 199 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6206ZZ on the 30×62×16 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6206 in a rated drive.",
      "Order the C3 internal-clearance version (6206 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6206-ZZ-NTN bearing?",
        "a": "A 6206-ZZ-NTN deep-groove ball bearing has a 30 mm bore, 62 mm outer diameter and 16 mm width (1.181 × 2.441 × 0.63 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How should 6206-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 30 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6206-ZZ-NTN need?",
        "a": "6206-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "What is the NTN suffix for a sealed 6206?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6206ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 30×62×16 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6206ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6206-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6206-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6206-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6206-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6206",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "206",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "206-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×62×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6206-zz",
      "6206zz",
      "6206-ZZ",
      "6206ZZ",
      "6206-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6306-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6306",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 72,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 29.5,
    "static_load_kN": 15,
    "fatigue_load_limit_kN": 1.14,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "weight_g": 360,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6306 carries bore code 06 = 30 mm. Outside diameter 72 mm and width 19 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 30 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "electric motors",
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Sizes around 30 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6306-NTN.",
      "The 63xx medium series gains rating at 30 mm bore through a 72 mm OD and 19 mm width; the heavier rolling elements also trade away some speed versus a 6206.",
      "Storage matters for open bearings: 6306-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 6300-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6306 units.",
      "A 30 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "The housing bore for the 72 mm OD should be round within IT7; an oval bore pinches the outer ring of 6306-NTN and shows up later as two-point loaded raceway wear.",
      "The open 6306 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 30 mm bore puts 6306 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 10000 r/min the grease limiting speed for 6306 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 29.5 kN dynamic load rating (C) and 15 kN static (C0), 1.14 kN fatigue load limit Cu, 6306 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 360 g, 6306 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 30×72×19 mm envelope of 6306 gives a D/d ratio of 2.40 and 21.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 29.5/15 kN load ratings, 1.14 kN fatigue load limit Cu NTN lists the grease limiting speed at 10000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 360 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6306 on the 30×72×19 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6306 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6306-NTN bearing?",
        "a": "A 6306-NTN deep-groove ball bearing has a 30 mm bore, 72 mm outer diameter and 19 mm width (1.181 × 2.835 × 0.748 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6306 bore code work?",
        "a": "The last two digits of 6306 are bore code 06, giving 06 × 5 = 30 mm bore. The 72 mm outside diameter and 19 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does no suffix on 6306 mean?",
        "a": "A bare 6306 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "What is the NTN order number for an open 6306?",
        "a": "NTN lists the open 6306 under the bare designation 6306; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 30 mm bore envelope."
      },
      {
        "q": "Is 6306 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6306-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6306-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6306-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6306",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "306",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "306-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6306",
      "6306-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6306-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6306LLU",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 72,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 29.5,
    "static_load_kN": 15,
    "fatigue_load_limit_kN": 1.14,
    "limiting_speed_rpm": 6600,
    "max_rpm": 6600,
    "weight_g": 360,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6306 carries bore code 06 = 30 mm. Outside diameter 72 mm and width 19 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 30 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6306LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Sizes around 30 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6306-2RS-NTN.",
      "The 63xx medium series gains rating at 30 mm bore through a 72 mm OD and 19 mm width; the heavier rolling elements also trade away some speed versus a 6206.",
      "Contact seals add drag and heat: 6306-2RS-NTN runs slower and cooler-limited than the open 6306; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 6306-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6306-2RS-NTN-C3. No clearance suffix means normal CN clearance.",
      "Measure the shaft, do not trust the drawing: a 30 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6306-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6306LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 30 mm bore puts 6306 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6600 r/min the grease limiting speed for 6306 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "At 29.5 kN dynamic load rating (C) and 15 kN static (C0), 1.14 kN fatigue load limit Cu, 6306 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 360 g, 6306 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 30×72×19 mm envelope of 6306 gives a D/d ratio of 2.40 and 21.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 29.5/15 kN load ratings, 1.14 kN fatigue load limit Cu NTN lists the grease limiting speed at 6600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 360 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6306LLU on the 30×72×19 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6306 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6306 is listed.",
      "Standard catalogue stock of 6306 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6306-2RS-NTN bearing?",
        "a": "A 6306-2RS-NTN deep-groove ball bearing has a 30 mm bore, 72 mm outer diameter and 19 mm width (1.181 × 2.835 × 0.748 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How should 6306-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 30 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6306-2RS-NTN need?",
        "a": "6306-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6306 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 6306?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6306LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 30×72×19 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6306 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6306LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6306-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6306-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6306-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6306",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "306",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "306-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6306-llu",
      "6306llu",
      "6306-2RS",
      "6306-2rs",
      "6306LLU",
      "6306-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6306-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6306LLB",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 72,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 29.5,
    "static_load_kN": 15,
    "fatigue_load_limit_kN": 1.14,
    "limiting_speed_rpm": 7900,
    "max_rpm": 7900,
    "weight_g": 360,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6306-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 06 by five gives the 30 mm bore; the 72 mm outside diameter and 19 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 30 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6306LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "At a 30 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6306-RSR-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 63xx medium series gains rating at 30 mm bore through a 72 mm OD and 19 mm width; the heavier rolling elements also trade away some speed versus a 6206.",
      "RSR low-friction seals on 6306-RSR-NTN run faster than contact-seal 6306-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6306-2RS instead.",
      "The non-contact lip of 6306-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 30 mm bore position before relying on it as sealed-for-life.",
      "Never mix components between two 6306-RSR-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Do not quieten a noisy bearing by preloading it: the 6300-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues this low-friction non-contact seal as 6306LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 30 mm bore puts 6306 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7900 r/min the grease limiting speed for 6306 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 29.5 kN dynamic load rating (C) and 15 kN static (C0), 1.14 kN fatigue load limit Cu, 6306 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 360 g, 6306 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 30×72×19 mm envelope of 6306 gives a D/d ratio of 2.40 and 21.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 29.5/15 kN load ratings, 1.14 kN fatigue load limit Cu NTN lists the grease limiting speed at 7900 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 360 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6306LLB on the 30×72×19 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6306 in a rated drive.",
      "Order the C3 internal-clearance version (6306 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Standard catalogue stock of 6306 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6306-RSR-NTN bearing?",
        "a": "A 6306-RSR-NTN deep-groove ball bearing has a 30 mm bore, 72 mm outer diameter and 19 mm width (1.181 × 2.835 × 0.748 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6306 bore code work?",
        "a": "The last two digits of 6306 are bore code 06, giving 06 × 5 = 30 mm bore. The 72 mm outside diameter and 19 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the RSR suffix on 6306-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "What is the NTN suffix for a sealed 6306?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6306LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 30×72×19 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6306 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6306LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6306-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6306-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6306-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6306",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "306",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "306-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6306-llb",
      "6306llb",
      "6306-RSR",
      "6306-rsr",
      "6306LLB",
      "6306-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6306-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6306ZZ",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 72,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 29.5,
    "static_load_kN": 15,
    "fatigue_load_limit_kN": 1.14,
    "limiting_speed_rpm": 7900,
    "max_rpm": 7900,
    "weight_g": 360,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6306 carries bore code 06 = 30 mm. Outside diameter 72 mm and width 19 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 30 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6306ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "A 30 mm shaft for 6306 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 63xx medium section at 30 mm bore gains dynamic rating through larger rolling elements on a 72 mm OD; the penalty is mass and a lower limiting speed than the 6206 — do not specify it for speed-critical shafts.",
      "ZZ shields are non-contact: 6306-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6306-2RS for that.",
      "Shielded 6306-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6300-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues the shielded version as 6306ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 30 mm bore puts 6306 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7900 r/min the grease limiting speed for 6306 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 29.5 kN dynamic load rating (C) and 15 kN static (C0), 1.14 kN fatigue load limit Cu, 6306 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 360 g, 6306 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 30×72×19 mm envelope of 6306 gives a D/d ratio of 2.40 and 21.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 29.5/15 kN load ratings, 1.14 kN fatigue load limit Cu NTN lists the grease limiting speed at 7900 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 360 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6306ZZ on the 30×72×19 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6306 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Order the C3 internal-clearance version (6306 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6306-ZZ-NTN bearing?",
        "a": "A 6306-ZZ-NTN deep-groove ball bearing has a 30 mm bore, 72 mm outer diameter and 19 mm width (1.181 × 2.835 × 0.748 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What internal clearance does 6306-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6306-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6306 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6306-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 30 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 6306?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6306ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 30×72×19 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6306 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6306ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6306-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6306-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6306-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6306-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6306",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "306",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "306-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×72×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6306-zz",
      "6306zz",
      "6306-ZZ",
      "6306ZZ",
      "6306-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6406-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6406",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 90,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 48,
    "static_load_kN": 23.9,
    "fatigue_load_limit_kN": 1.86,
    "limiting_speed_rpm": 8800,
    "max_rpm": 8800,
    "weight_g": 735,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6406 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the heavy 64xx section (diameter series 4 of ISO 15), multiplying bore code 06 by five gives the 30 mm bore; the 90 mm outside diameter and 23 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 30 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "At a 30 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6406-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 64xx heavy section at 30 mm bore exists for high radial load at moderate rpm; its 90 mm OD and 23 mm width demand a larger housing, and grease life at motor speeds is short — treat it as a low-speed, high-load choice.",
      "Storage matters for open bearings: 6406-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 6400-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6406 units.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6400-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Shaft and housing fillets must clear the bearing chamfer so the 23 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "The open 6406 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 30 mm bore puts 6406 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8800 r/min the grease limiting speed for 6406 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6406 at 48 kN dynamic (C) and 23.9 kN static (C0), 1.86 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 735 g, 6406 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 30×90×23 mm envelope of 6406 gives a D/d ratio of 3.00 and 30.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 48/23.9 kN load ratings, 1.86 kN fatigue load limit Cu NTN lists the grease limiting speed at 8800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 735 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6406 on the 30×90×23 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6406 in a rated drive.",
      "Order the C3 internal-clearance version (6406 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6406 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6406-NTN bearing?",
        "a": "A 6406-NTN deep-groove ball bearing has a 30 mm bore, 90 mm outer diameter and 23 mm width (1.181 × 3.543 × 0.906 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6400 compare with other series at the same 30 mm bore?",
        "a": "The '4' is the heavy diameter series: 90×23 mm, 30.0 mm radial section at 30 mm bore — the highest-capacity single-row 6xx option here, aimed at lower-speed, high-load shafts."
      },
      {
        "q": "Are 6406 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6406 uses the same ISO 15 envelope (30×90×23 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 6406?",
        "a": "NTN lists the open 6406 under the bare designation 6406; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 30 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6406 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6406 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6406-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6406-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 30×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6406",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 30×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6406",
      "6406-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6406-ZZ",
    "brand": "NTN",
    "manufacturer_designation": "6406ZZ",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 30,
    "D_mm": 90,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 48,
    "static_load_kN": 23.9,
    "fatigue_load_limit_kN": 1.86,
    "limiting_speed_rpm": 8800,
    "max_rpm": 8800,
    "weight_g": 735,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6406-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the heavy 64xx section (diameter series 4 of ISO 15), multiplying bore code 06 by five gives the 30 mm bore; the 90 mm outside diameter and 23 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 30 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6406ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Sizes around 30 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6406-ZZ.",
      "The 64xx heavy section at 30 mm bore (90 mm OD) is built for high-load, lower-speed duty; specifying it in a high-rpm motor gives excess heat and short grease life — use 62/63 there.",
      "ZZ shields are non-contact: 6406-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6406-2RS for that.",
      "Do not wash 6406-ZZ in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Do not quieten a noisy bearing by preloading it: the 6400-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues the shielded version as 6406ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 30 mm bore puts 6406 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8800 r/min the grease limiting speed for 6406 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6406 at 48 kN dynamic (C) and 23.9 kN static (C0), 1.86 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 735 g, 6406 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 30×90×23 mm envelope of 6406 gives a D/d ratio of 3.00 and 30.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 48/23.9 kN load ratings, 1.86 kN fatigue load limit Cu NTN lists the grease limiting speed at 8800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 735 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6406ZZ on the 30×90×23 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6406 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6406-ZZ bearing?",
        "a": "A 6406-ZZ deep-groove ball bearing has a 30 mm bore, 90 mm outer diameter and 23 mm width (1.181 × 3.543 × 0.906 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 6406-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 6400 compare with other series at the same 30 mm bore?",
        "a": "The '4' is the heavy diameter series: 90×23 mm, 30.0 mm radial section at 30 mm bore — the highest-capacity single-row 6xx option here, aimed at lower-speed, high-load shafts."
      },
      {
        "q": "What is the NTN suffix for a sealed 6406?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6406ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 30×90×23 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6406 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6406ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6406-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 30×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6406-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 30×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6406",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 30×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6406-zz",
      "6406zz",
      "6406-ZZ",
      "6406ZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61807-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6807JR",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 47,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.45,
    "static_load_kN": 4.05,
    "fatigue_load_limit_kN": 0.27,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "weight_g": 29,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61807 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 07 by five gives the 35 mm bore; the 47 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 35 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "At a 35 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61807-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "Only 6.0 mm of radial section separates bore and OD on the 618xx series at 35 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6207.",
      "Storage matters for open bearings: 61807-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 61800-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61807 units.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61807-NTN-C3. No clearance suffix means normal CN clearance.",
      "The housing bore for the 47 mm OD should be round within IT7; an oval bore pinches the outer ring of 61807-NTN and shows up later as two-point loaded raceway wear.",
      "The open 61807 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 35 mm bore puts 61807 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61807 at 13000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 61807 at 5.45 kN dynamic (C) and 4.05 kN static (C0), 0.27 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 29 g, 61807 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 35×47×7 mm envelope of 61807 gives a D/d ratio of 1.34 and only 6.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 5.45/4.05 kN load ratings, 0.27 kN fatigue load limit Cu NTN lists the grease limiting speed at 13000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 29 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6807JR on the 35×47×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61807 in a rated drive.",
      "Order the C3 internal-clearance version (61807 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61807-NTN bearing?",
        "a": "A 61807-NTN deep-groove ball bearing has a 35 mm bore, 47 mm outer diameter and 7 mm width (1.378 × 1.85 × 0.276 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 61807 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61807 uses the same ISO 15 envelope (35×47×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 61807-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61807-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61807 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 61807?",
        "a": "NTN lists the open 61807 under the bare designation 6807JR; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 35 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6807JR?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61807-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61807-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6807jr",
      "61807",
      "6807JR",
      "61807-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61807-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6807JRLLU",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 47,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.45,
    "static_load_kN": 4.05,
    "fatigue_load_limit_kN": 0.27,
    "limiting_speed_rpm": 7600,
    "max_rpm": 7600,
    "weight_g": 29,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61807-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 07 by five gives the 35 mm bore; the 47 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 35 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6807JRLLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "At a 35 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61807-2RS-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 618xx thin section at 35 mm bore has only a 6.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6207.",
      "Contact seals add drag and heat: 61807-2RS-NTN runs slower and cooler-limited than the open 61807; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 61807-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 47 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61807-2RS-NTN.",
      "Measure the shaft, do not trust the drawing: a 35 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61807-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6807JRLLU (suffix RLLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 35 mm bore puts 61807 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7600 r/min the grease limiting speed for 61807 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 61807 at 5.45 kN dynamic (C) and 4.05 kN static (C0), 0.27 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 29 g, 61807 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 35×47×7 mm envelope of 61807 gives a D/d ratio of 1.34 and only 6.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 5.45/4.05 kN load ratings, 0.27 kN fatigue load limit Cu NTN lists the grease limiting speed at 7600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 29 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6807JRLLU on the 35×47×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61807 in a rated drive.",
      "Order the C3 internal-clearance version (61807 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61807-2RS-NTN bearing?",
        "a": "A 61807-2RS-NTN deep-groove ball bearing has a 35 mm bore, 47 mm outer diameter and 7 mm width (1.378 × 1.85 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What lubrication does 61807-2RS-NTN need?",
        "a": "61807-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61807 with a housing grease fitting instead."
      },
      {
        "q": "How does the 61807 bore code work?",
        "a": "The last two digits of 61807 are bore code 07, giving 07 × 5 = 35 mm bore. The 47 mm outside diameter and 7 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 61807?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6807JRLLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×47×7 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6807JRLLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61807-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61807-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61807-llu",
      "6807jrllu",
      "6807llu",
      "61807-2RS",
      "61807-2rs",
      "6807JRLLU",
      "61807-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61807-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6807JRLLB",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 47,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.45,
    "static_load_kN": 4.05,
    "fatigue_load_limit_kN": 0.27,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "weight_g": 29,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61807 carries bore code 07 = 35 mm. Outside diameter 47 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6807JRLLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "A 35 mm shaft for 61807 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 618xx thin section at 35 mm bore has only a 6.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6207.",
      "RSR low-friction seals on 61807-RSR-NTN run faster than contact-seal 61807-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61807-2RS instead.",
      "The non-contact lip of 61807-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 35 mm bore position before relying on it as sealed-for-life.",
      "Do not quieten a noisy bearing by preloading it: the 61800-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "Shaft and housing fillets must clear the bearing chamfer so the 7 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues this low-friction non-contact seal as 6807JRLLB (suffix RLLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 35 mm bore puts 61807 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61807 at 13000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 61807 at 5.45 kN dynamic (C) and 4.05 kN static (C0), 0.27 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 29 g, 61807 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 35×47×7 mm envelope of 61807 gives a D/d ratio of 1.34 and only 6.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 5.45/4.05 kN load ratings, 0.27 kN fatigue load limit Cu NTN lists the grease limiting speed at 13000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 29 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6807JRLLB on the 35×47×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61807 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61807 is listed.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61807-RSR-NTN bearing?",
        "a": "A 61807-RSR-NTN deep-groove ball bearing has a 35 mm bore, 47 mm outer diameter and 7 mm width (1.378 × 1.85 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What does the RSR suffix on 61807-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "How does the 61800 compare with other series at the same 35 mm bore?",
        "a": "618 is an extra-thin section: 47×7 mm, only 6.0 mm radial section at 35 mm bore, far smaller than a 6207, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "What is the NTN suffix for a sealed 61807?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6807JRLLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×47×7 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61807 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6807JRLLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61807-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61807-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61807-llb",
      "6807jrllb",
      "6807llb",
      "61807-RSR",
      "61807-rsr",
      "6807JRLLB",
      "61807-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61807-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6807JRZZ",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 47,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.45,
    "static_load_kN": 4.05,
    "fatigue_load_limit_kN": 0.27,
    "limiting_speed_rpm": 13000,
    "max_rpm": 13000,
    "weight_g": 29,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61807 carries bore code 07 = 35 mm. Outside diameter 47 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6807JRZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "At a 35 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61807-ZZ-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 618xx thin section at 35 mm bore has only a 6.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6207.",
      "ZZ shields are non-contact: 61807-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61807-2RS for that.",
      "Shielded 61807-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61807-ZZ-NTN-C3. No clearance suffix means normal CN clearance.",
      "Vibration during standstill brinells the raceways of a 35 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues the shielded version as 6807JRZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 35 mm bore puts 61807 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61807 at 13000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.",
      "NTN rates 61807 at 5.45 kN dynamic (C) and 4.05 kN static (C0), 0.27 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 29 g, 61807 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 35×47×7 mm envelope of 61807 gives a D/d ratio of 1.34 and only 6.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 5.45/4.05 kN load ratings, 0.27 kN fatigue load limit Cu NTN lists the grease limiting speed at 13000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 29 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6807JRZZ on the 35×47×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61807 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61807-ZZ-NTN bearing?",
        "a": "A 61807-ZZ-NTN deep-groove ball bearing has a 35 mm bore, 47 mm outer diameter and 7 mm width (1.378 × 1.85 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 61807-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 61800 compare with other series at the same 35 mm bore?",
        "a": "618 is an extra-thin section: 47×7 mm, only 6.0 mm radial section at 35 mm bore, far smaller than a 6207, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "What is the NTN suffix for a sealed 61807?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6807JRZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×47×7 mm ISO 15 envelope."
      },
      {
        "q": "Is 6807JRZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61807-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61807-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61807-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×47×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61807-zz",
      "6807jrzz",
      "6807zz",
      "61807-ZZ",
      "6807JRZZ",
      "61807-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61907-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6907",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 55,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.6,
    "static_load_kN": 6.85,
    "fatigue_load_limit_kN": 0.49,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 74,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61907 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 07 by five gives the 35 mm bore; the 55 mm outside diameter and 10 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 35 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "A 35 mm shaft for 61907 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 619xx thin section (10.0 mm section height at 35 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "Storage matters for open bearings: 61907-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 61900-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61907 units.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61900-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Never mix components between two 61907-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "The open 61907 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 35 mm bore puts 61907 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61907 at 12000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 61907 at 10.6 kN dynamic (C) and 6.85 kN static (C0), 0.49 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 74 g, 61907 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 35×55×10 mm envelope of 61907 gives a D/d ratio of 1.57 and 10.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 10.6/6.85 kN load ratings, 0.49 kN fatigue load limit Cu NTN lists the grease limiting speed at 12000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 74 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6907 on the 35×55×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61907 in a rated drive.",
      "Order the C3 internal-clearance version (61907 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61907-NTN bearing?",
        "a": "A 61907-NTN deep-groove ball bearing has a 35 mm bore, 55 mm outer diameter and 10 mm width (1.378 × 2.165 × 0.394 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 61907 bore code work?",
        "a": "The last two digits of 61907 are bore code 07, giving 07 × 5 = 35 mm bore. The 55 mm outside diameter and 10 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does no suffix on 61907 mean?",
        "a": "A bare 61907 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "What is the NTN order number for an open 61907?",
        "a": "NTN lists the open 61907 under the bare designation 6907; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 35 mm bore envelope."
      },
      {
        "q": "Is 6907 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61907-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61907-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6907",
      "61907",
      "61907-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61907-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6907LLU",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 55,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.6,
    "static_load_kN": 6.85,
    "fatigue_load_limit_kN": 0.49,
    "limiting_speed_rpm": 7100,
    "max_rpm": 7100,
    "weight_g": 74,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61907 carries bore code 07 = 35 mm. Outside diameter 55 mm and width 10 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6907LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At a 35 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61907-2RS-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 619xx thin section at 35 mm bore (10.0 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "Contact seals add drag and heat: 61907-2RS-NTN runs slower and cooler-limited than the open 61907; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 61907-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Shaft and housing fillets must clear the bearing chamfer so the 10 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61907-2RS-NTN-C3. No clearance suffix means normal CN clearance.",
      "NTN catalogues the contact-sealed version as 6907LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 35 mm bore puts 61907 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7100 r/min the grease limiting speed for 61907 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 61907 at 10.6 kN dynamic (C) and 6.85 kN static (C0), 0.49 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 74 g, 61907 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 35×55×10 mm envelope of 61907 gives a D/d ratio of 1.57 and 10.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 10.6/6.85 kN load ratings, 0.49 kN fatigue load limit Cu NTN lists the grease limiting speed at 7100 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 74 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6907LLU on the 35×55×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61907 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61907-2RS-NTN bearing?",
        "a": "A 61907-2RS-NTN deep-groove ball bearing has a 35 mm bore, 55 mm outer diameter and 10 mm width (1.378 × 2.165 × 0.394 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What internal clearance does 61907-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61907-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61907 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61907-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 35 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 61907?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6907LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×55×10 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6907LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61907-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61907-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61907-llu",
      "6907llu",
      "61907-2RS",
      "61907-2rs",
      "6907LLU",
      "61907-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61907-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6907LLB",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 55,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.6,
    "static_load_kN": 6.85,
    "fatigue_load_limit_kN": 0.49,
    "limiting_speed_rpm": 8500,
    "max_rpm": 8500,
    "weight_g": 74,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61907 carries bore code 07 = 35 mm. Outside diameter 55 mm and width 10 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6907LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At a 35 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61907-RSR-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 619xx thin section (10.0 mm section height at 35 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "RSR low-friction seals on 61907-RSR-NTN run faster than contact-seal 61907-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61907-2RS instead.",
      "The low-drag lip of 61907-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 55 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61907-RSR-NTN.",
      "Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues this low-friction non-contact seal as 6907LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 35 mm bore puts 61907 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8500 r/min the grease limiting speed for 61907 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61907 at 10.6 kN dynamic (C) and 6.85 kN static (C0), 0.49 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 74 g, 61907 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 35×55×10 mm envelope of 61907 gives a D/d ratio of 1.57 and 10.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 10.6/6.85 kN load ratings, 0.49 kN fatigue load limit Cu NTN lists the grease limiting speed at 8500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 74 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6907LLB on the 35×55×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61907 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Standard catalogue stock of 61907 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61907-RSR-NTN bearing?",
        "a": "A 61907-RSR-NTN deep-groove ball bearing has a 35 mm bore, 55 mm outer diameter and 10 mm width (1.378 × 2.165 × 0.394 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What does the RSR suffix on 61907-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "How does the 61900 compare with other series at the same 35 mm bore?",
        "a": "619 is a thin section one step above 618: 55×10 mm with a 10.0 mm radial section at 35 mm bore; a 6207 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "What is the NTN suffix for a sealed 61907?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6907LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×55×10 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61907 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6907LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61907-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61907-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61907-llb",
      "6907llb",
      "61907-RSR",
      "61907-rsr",
      "6907LLB",
      "61907-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61907-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6907ZZ",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 55,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 10.6,
    "static_load_kN": 6.85,
    "fatigue_load_limit_kN": 0.49,
    "limiting_speed_rpm": 8500,
    "max_rpm": 8500,
    "weight_g": 74,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61907-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 07 by five gives the 35 mm bore; the 55 mm outside diameter and 10 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 35 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6907ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Sizes around 35 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 61907-ZZ-NTN.",
      "The 619xx thin section at 35 mm bore (10.0 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "Do not wash 61907-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 61907-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "A 35 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 10 mm-wide ring of 61907-ZZ-NTN drags the lip and overheats it.",
      "NTN catalogues the shielded version as 6907ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 35 mm bore puts 61907 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8500 r/min the grease limiting speed for 61907 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61907 at 10.6 kN dynamic (C) and 6.85 kN static (C0), 0.49 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 74 g, 61907 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 35×55×10 mm envelope of 61907 gives a D/d ratio of 1.57 and 10.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 10.6/6.85 kN load ratings, 0.49 kN fatigue load limit Cu NTN lists the grease limiting speed at 8500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 74 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6907ZZ on the 35×55×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61907 in a rated drive.",
      "Order the C3 internal-clearance version (61907 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61907-ZZ-NTN bearing?",
        "a": "A 61907-ZZ-NTN deep-groove ball bearing has a 35 mm bore, 55 mm outer diameter and 10 mm width (1.378 × 2.165 × 0.394 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What internal clearance does 61907-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61907-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61907 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61907-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 35 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 61907?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6907ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×55×10 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6907ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61907-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61907-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61907-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61907-zz",
      "6907zz",
      "61907-ZZ",
      "6907ZZ",
      "61907-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "16007-NTN",
    "brand": "NTN",
    "manufacturer_designation": "16007",
    "series": "16000-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 62,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 12.9,
    "static_load_kN": 8.2,
    "fatigue_load_limit_kN": 0.6,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 16000-series (the narrow extra-light section of ISO 15) the last two digits encode the bore: 16007 carries bore code 07 = 35 mm. Outside diameter 62 mm and width 9 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "A 35 mm shaft for 16007 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "Because the 160xx narrow section shares the 62 mm OD of the 6007 at 35 mm bore but is only 9 mm wide, a housing machined for the wider bearing needs a spacer or relocated circlip — never assume width interchangeability.",
      "The open 16007-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 35×62×9 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 16007-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 16007-NTN-C3. No clearance suffix means normal CN clearance.",
      "Measure the shaft, do not trust the drawing: a 35 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 16007-NTN.",
      "The open 16007 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 35 mm bore puts 16007 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 16007 at 12000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 16007 at 12.9 kN dynamic (C) and 8.2 kN static (C0), 0.6 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 110 g, 16007 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 35×62×9 mm envelope of 16007 gives a D/d ratio of 1.77 and 13.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 12.9/8.2 kN load ratings, 0.6 kN fatigue load limit Cu NTN lists the grease limiting speed at 12000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 110 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 16007 on the 35×62×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 16007 in a rated drive.",
      "Order the C3 internal-clearance version (16007 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Standard catalogue stock of 16007 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 16007-NTN bearing?",
        "a": "A 16007-NTN deep-groove ball bearing has a 35 mm bore, 62 mm outer diameter and 9 mm width (1.378 × 2.441 × 0.354 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What does no suffix on 16007 mean?",
        "a": "A bare 16007 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "How does the 16000 compare with other series at the same 35 mm bore?",
        "a": "160 is the narrow extra-light section: 62×9 mm with a 13.5 mm radial section at 35 mm bore. It has the same bore and outside diameter as the 6007 but a narrower ring, so the two are not width-interchangeable; it appears in the manufacturer catalogues used on this site."
      },
      {
        "q": "What is the NTN order number for an open 16007?",
        "a": "NTN lists the open 16007 under the bare designation 16007; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 35 mm bore envelope."
      },
      {
        "q": "Is 16007 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "16007",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 35×62×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "16007",
      "16007-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6007-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6007",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 62,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 17.7,
    "static_load_kN": 10.3,
    "fatigue_load_limit_kN": 0.81,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 155,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6007 carries bore code 07 = 35 mm. Outside diameter 62 mm and width 14 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "A 35 mm shaft for 6007 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 60xx extra-light section at 35 mm bore uses a smaller 62 mm OD than a 6207; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "The open 6007-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 35×62×14 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 6000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6007 units.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 62 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6007-NTN.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6000-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "The open 6007 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 35 mm bore puts 6007 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 6007 at 12000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "At 17.7 kN dynamic load rating (C) and 10.3 kN static (C0), 0.81 kN fatigue load limit Cu, 6007 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 155 g, 6007 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 35×62×14 mm envelope of 6007 gives a D/d ratio of 1.77 and 13.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 17.7/10.3 kN load ratings, 0.81 kN fatigue load limit Cu NTN lists the grease limiting speed at 12000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 155 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6007 on the 35×62×14 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6007 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Order the C3 internal-clearance version (6007 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6007-NTN bearing?",
        "a": "A 6007-NTN deep-groove ball bearing has a 35 mm bore, 62 mm outer diameter and 14 mm width (1.378 × 2.441 × 0.551 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6000 compare with other series at the same 35 mm bore?",
        "a": "The second digit is the diameter series: 60 is the smallest standard section (62×14 mm, 13.5 mm radial section) at 35 mm bore — below 62/63/64 in load capacity, for light loads in compact spaces."
      },
      {
        "q": "Are 6007 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6007 uses the same ISO 15 envelope (35×62×14 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 6007?",
        "a": "NTN lists the open 6007 under the bare designation 6007; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 35 mm bore envelope."
      },
      {
        "q": "Is 6007 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6007-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6007-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6007-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6007",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6007",
      "6007-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6007-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6007LLU",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 62,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 17.7,
    "static_load_kN": 10.3,
    "fatigue_load_limit_kN": 0.81,
    "limiting_speed_rpm": 6800,
    "max_rpm": 6800,
    "weight_g": 155,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6007 carries bore code 07 = 35 mm. Outside diameter 62 mm and width 14 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6007LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Sizes around 35 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6007-2RS-NTN.",
      "The 60xx extra-light section at 35 mm bore uses a smaller 62 mm OD than a 6207; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "Contact seals add drag and heat: 6007-2RS-NTN runs slower and cooler-limited than the open 6007; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 6007-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "The housing bore for the 62 mm OD should be round within IT7; an oval bore pinches the outer ring of 6007-2RS-NTN and shows up later as two-point loaded raceway wear.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 14 mm-wide ring of 6007-2RS-NTN drags the lip and overheats it.",
      "NTN catalogues the contact-sealed version as 6007LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 35 mm bore puts 6007 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6800 r/min the grease limiting speed for 6007 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "At 17.7 kN dynamic load rating (C) and 10.3 kN static (C0), 0.81 kN fatigue load limit Cu, 6007 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 155 g, 6007 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 35×62×14 mm envelope of 6007 gives a D/d ratio of 1.77 and 13.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 17.7/10.3 kN load ratings, 0.81 kN fatigue load limit Cu NTN lists the grease limiting speed at 6800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 155 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6007LLU on the 35×62×14 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6007 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Order the C3 internal-clearance version (6007 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6007-2RS-NTN bearing?",
        "a": "A 6007-2RS-NTN deep-groove ball bearing has a 35 mm bore, 62 mm outer diameter and 14 mm width (1.378 × 2.441 × 0.551 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What internal clearance does 6007-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6007-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6007 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6007-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 35 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 6007?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6007LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×62×14 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6007 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6007LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6007-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6007-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6007-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6007",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6007-llu",
      "6007llu",
      "6007-2RS",
      "6007-2rs",
      "6007LLU",
      "6007-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6007-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6007LLB",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 62,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 17.7,
    "static_load_kN": 10.3,
    "fatigue_load_limit_kN": 0.81,
    "limiting_speed_rpm": 8200,
    "max_rpm": 8200,
    "weight_g": 155,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6007-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 07 by five gives the 35 mm bore; the 62 mm outside diameter and 14 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 35 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6007LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "At a 35 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6007-RSR-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "Choosing the 60xx extra-light section saves radial space at 35 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6207 before committing to the smaller envelope.",
      "RSR low-friction seals on 6007-RSR-NTN run faster than contact-seal 6007-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6007-2RS instead.",
      "The non-contact lip of 6007-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 35 mm bore position before relying on it as sealed-for-life.",
      "The housing bore for the 62 mm OD should be round within IT7; an oval bore pinches the outer ring of 6007-RSR-NTN and shows up later as two-point loaded raceway wear.",
      "Never mix components between two 6007-RSR-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues this low-friction non-contact seal as 6007LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 35 mm bore puts 6007 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8200 r/min the grease limiting speed for 6007 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 17.7 kN dynamic load rating (C) and 10.3 kN static (C0), 0.81 kN fatigue load limit Cu, 6007 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 155 g, 6007 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 35×62×14 mm envelope of 6007 gives a D/d ratio of 1.77 and 13.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 17.7/10.3 kN load ratings, 0.81 kN fatigue load limit Cu NTN lists the grease limiting speed at 8200 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 155 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6007LLB on the 35×62×14 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6007 in a rated drive.",
      "Standard catalogue stock of 6007 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6007 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6007-RSR-NTN bearing?",
        "a": "A 6007-RSR-NTN deep-groove ball bearing has a 35 mm bore, 62 mm outer diameter and 14 mm width (1.378 × 2.441 × 0.551 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How should 6007-RSR-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 35 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6007-RSR-NTN need?",
        "a": "6007-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6007 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 6007?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6007LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×62×14 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6007LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6007-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6007-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6007-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6007",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6007-llb",
      "6007llb",
      "6007-RSR",
      "6007-rsr",
      "6007LLB",
      "6007-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6007-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6007ZZ",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 62,
    "B_mm": 14,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 17.7,
    "static_load_kN": 10.3,
    "fatigue_load_limit_kN": 0.81,
    "limiting_speed_rpm": 8200,
    "max_rpm": 8200,
    "weight_g": 155,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6007 carries bore code 07 = 35 mm. Outside diameter 62 mm and width 14 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6007ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers",
      "electric motors"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "A 35 mm shaft for 6007 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 60xx extra-light section at 35 mm bore uses a smaller 62 mm OD than a 6207; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "Do not wash 6007-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6007-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "The housing bore for the 62 mm OD should be round within IT7; an oval bore pinches the outer ring of 6007-ZZ-NTN and shows up later as two-point loaded raceway wear.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 14 mm-wide ring of 6007-ZZ-NTN drags the lip and overheats it.",
      "NTN catalogues the shielded version as 6007ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 35 mm bore puts 6007 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8200 r/min the grease limiting speed for 6007 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 17.7 kN dynamic load rating (C) and 10.3 kN static (C0), 0.81 kN fatigue load limit Cu, 6007 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 155 g, 6007 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 35×62×14 mm envelope of 6007 gives a D/d ratio of 1.77 and 13.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 17.7/10.3 kN load ratings, 0.81 kN fatigue load limit Cu NTN lists the grease limiting speed at 8200 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 155 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6007ZZ on the 35×62×14 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6007 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6007-ZZ-NTN bearing?",
        "a": "A 6007-ZZ-NTN deep-groove ball bearing has a 35 mm bore, 62 mm outer diameter and 14 mm width (1.378 × 2.441 × 0.551 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How should 6007-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 35 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6007-ZZ-NTN need?",
        "a": "6007-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "What is the NTN suffix for a sealed 6007?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6007ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×62×14 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6007 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6007ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6007-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6007-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6007-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6007-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6007",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×62×14 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6007-zz",
      "6007zz",
      "6007-ZZ",
      "6007ZZ",
      "6007-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6207-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6207",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 72,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 28.4,
    "static_load_kN": 15.3,
    "fatigue_load_limit_kN": 1.09,
    "limiting_speed_rpm": 9800,
    "max_rpm": 9800,
    "weight_g": 288,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6207 carries bore code 07 = 35 mm. Outside diameter 72 mm and width 17 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Sizes around 35 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6207-NTN.",
      "The 62xx light series is the default general-purpose section at 35 mm bore; before upgrading to a 6307 for extra capacity, confirm the housing accepts a 72 mm OD and 17 mm width — it is not a drop-in swap.",
      "The open 6207-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 35×72×17 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6207-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Shaft and housing fillets must clear the bearing chamfer so the 17 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6200-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "The open 6207 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 35 mm bore puts 6207 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 9800 r/min the grease limiting speed for 6207 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 28.4 kN dynamic load rating (C) and 15.3 kN static (C0), 1.09 kN fatigue load limit Cu, 6207 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 288 g, 6207 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 35×72×17 mm envelope of 6207 gives a D/d ratio of 2.06 and 18.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 28.4/15.3 kN load ratings, 1.09 kN fatigue load limit Cu NTN lists the grease limiting speed at 9800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 288 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6207 on the 35×72×17 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6207 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6207 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6207-NTN bearing?",
        "a": "A 6207-NTN deep-groove ball bearing has a 35 mm bore, 72 mm outer diameter and 17 mm width (1.378 × 2.835 × 0.669 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 6207 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6207 uses the same ISO 15 envelope (35×72×17 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 6207-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6207-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6207 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 6207?",
        "a": "NTN lists the open 6207 under the bare designation 6207; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 35 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6207?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6207-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6207-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6207-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6207",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "207",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "207-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6207",
      "6207-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6207-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6207LLU",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 72,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 28.4,
    "static_load_kN": 15.3,
    "fatigue_load_limit_kN": 1.09,
    "limiting_speed_rpm": 6300,
    "max_rpm": 6300,
    "weight_g": 288,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6207 carries bore code 07 = 35 mm. Outside diameter 72 mm and width 17 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6207LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "fans and blowers",
      "electric motors",
      "centrifugal pumps",
      "small gearboxes"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "At a 35 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6207-2RS-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "At 35 mm bore the 62xx light series is the workhorse section; its 72×17 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "Heat is the enemy of the sealed 6207-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 6207-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 17 mm-wide ring of 6207-2RS-NTN drags the lip and overheats it.",
      "Never mix components between two 6207-2RS-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the contact-sealed version as 6207LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 35 mm bore puts 6207 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6300 r/min the grease limiting speed for 6207 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "At 28.4 kN dynamic load rating (C) and 15.3 kN static (C0), 1.09 kN fatigue load limit Cu, 6207 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 288 g, 6207 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 35×72×17 mm envelope of 6207 gives a D/d ratio of 2.06 and 18.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 28.4/15.3 kN load ratings, 1.09 kN fatigue load limit Cu NTN lists the grease limiting speed at 6300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 288 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6207LLU on the 35×72×17 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6207 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6207 is listed.",
      "Order the C3 internal-clearance version (6207 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6207-2RS-NTN bearing?",
        "a": "A 6207-2RS-NTN deep-groove ball bearing has a 35 mm bore, 72 mm outer diameter and 17 mm width (1.378 × 2.835 × 0.669 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 6207 bore code work?",
        "a": "The last two digits of 6207 are bore code 07, giving 07 × 5 = 35 mm bore. The 72 mm outside diameter and 17 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the 2RS suffix on 6207-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "What is the NTN suffix for a sealed 6207?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6207LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×72×17 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6207 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6207LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6207-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6207-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6207-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6207",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "207",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "207-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6207-llu",
      "6207llu",
      "6207-2RS",
      "6207-2rs",
      "6207LLU",
      "6207-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6207-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6207LLB",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 72,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 28.4,
    "static_load_kN": 15.3,
    "fatigue_load_limit_kN": 1.09,
    "limiting_speed_rpm": 7600,
    "max_rpm": 7600,
    "weight_g": 288,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6207 carries bore code 07 = 35 mm. Outside diameter 72 mm and width 17 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6207LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers",
      "electric motors"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Sizes around 35 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6207-RSR-NTN.",
      "At 35 mm bore the 62xx light series is the workhorse section; its 72×17 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "RSR low-friction seals on 6207-RSR-NTN run faster than contact-seal 6207-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6207-2RS instead.",
      "The non-contact lip of 6207-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 35 mm bore position before relying on it as sealed-for-life.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 72 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6207-RSR-NTN.",
      "A 35 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues this low-friction non-contact seal as 6207LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 35 mm bore puts 6207 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7600 r/min the grease limiting speed for 6207 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 28.4 kN dynamic load rating (C) and 15.3 kN static (C0), 1.09 kN fatigue load limit Cu, 6207 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 288 g, 6207 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 35×72×17 mm envelope of 6207 gives a D/d ratio of 2.06 and 18.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 28.4/15.3 kN load ratings, 1.09 kN fatigue load limit Cu NTN lists the grease limiting speed at 7600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 288 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6207LLB on the 35×72×17 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6207 in a rated drive.",
      "Order the C3 internal-clearance version (6207 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6207 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6207-RSR-NTN bearing?",
        "a": "A 6207-RSR-NTN deep-groove ball bearing has a 35 mm bore, 72 mm outer diameter and 17 mm width (1.378 × 2.835 × 0.669 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How should 6207-RSR-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 35 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6207-RSR-NTN need?",
        "a": "6207-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6207 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 6207?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6207LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×72×17 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6207LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6207-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6207-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6207-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6207",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "207",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "207-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6207-llb",
      "6207llb",
      "6207-RSR",
      "6207-rsr",
      "6207LLB",
      "6207-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6207-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6207ZZ",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 72,
    "B_mm": 17,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 28.4,
    "static_load_kN": 15.3,
    "fatigue_load_limit_kN": 1.09,
    "limiting_speed_rpm": 7600,
    "max_rpm": 7600,
    "weight_g": 288,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6207 carries bore code 07 = 35 mm. Outside diameter 72 mm and width 17 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6207ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers",
      "electric motors"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Sizes around 35 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6207-ZZ-NTN.",
      "At 35 mm bore the 62xx light series is the workhorse section; its 72×17 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "ZZ shields are non-contact: 6207-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6207-2RS for that.",
      "Shielded 6207-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Vibration during standstill brinells the raceways of a 35 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Do not quieten a noisy bearing by preloading it: the 6200-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues the shielded version as 6207ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 35 mm bore puts 6207 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7600 r/min the grease limiting speed for 6207 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 28.4 kN dynamic load rating (C) and 15.3 kN static (C0), 1.09 kN fatigue load limit Cu, 6207 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 288 g, 6207 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 35×72×17 mm envelope of 6207 gives a D/d ratio of 2.06 and 18.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 28.4/15.3 kN load ratings, 1.09 kN fatigue load limit Cu NTN lists the grease limiting speed at 7600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 288 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6207ZZ on the 35×72×17 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6207 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Standard catalogue stock of 6207 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6207-ZZ-NTN bearing?",
        "a": "A 6207-ZZ-NTN deep-groove ball bearing has a 35 mm bore, 72 mm outer diameter and 17 mm width (1.378 × 2.835 × 0.669 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "Are 6207 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6207 uses the same ISO 15 envelope (35×72×17 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 6207-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6207-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6207 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 6207?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6207ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×72×17 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6207 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6207ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6207-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6207-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6207-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6207-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6207",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "207",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "207-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×72×17 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6207-zz",
      "6207zz",
      "6207-ZZ",
      "6207ZZ",
      "6207-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6307-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6307",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 80,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 37,
    "static_load_kN": 19.1,
    "fatigue_load_limit_kN": 1.47,
    "limiting_speed_rpm": 8800,
    "max_rpm": 8800,
    "weight_g": 457,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6307 carries bore code 07 = 35 mm. Outside diameter 80 mm and width 21 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "electric motors",
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Sizes around 35 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6307-NTN.",
      "The 63xx medium section at 35 mm bore gains dynamic rating through larger rolling elements on a 80 mm OD; the penalty is mass and a lower limiting speed than the 6207 — do not specify it for speed-critical shafts.",
      "The open 6307-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 35×80×21 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6307-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Shaft and housing fillets must clear the bearing chamfer so the 21 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Measure the shaft, do not trust the drawing: a 35 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6307-NTN.",
      "The open 6307 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 35 mm bore puts 6307 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8800 r/min the grease limiting speed for 6307 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6307 at 37 kN dynamic (C) and 19.1 kN static (C0), 1.47 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 457 g, 6307 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 35×80×21 mm envelope of 6307 gives a D/d ratio of 2.29 and 22.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 37/19.1 kN load ratings, 1.47 kN fatigue load limit Cu NTN lists the grease limiting speed at 8800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 457 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6307 on the 35×80×21 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6307 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6307-NTN bearing?",
        "a": "A 6307-NTN deep-groove ball bearing has a 35 mm bore, 80 mm outer diameter and 21 mm width (1.378 × 3.15 × 0.827 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6300 compare with other series at the same 35 mm bore?",
        "a": "The '3' is the medium diameter series: 80×21 mm, 22.5 mm radial section at 35 mm bore, carrying more load than a 6207 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "Are 6307 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6307 uses the same ISO 15 envelope (35×80×21 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 6307?",
        "a": "NTN lists the open 6307 under the bare designation 6307; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 35 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6307 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6307 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6307-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6307-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "307",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "307-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6307",
      "6307-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6307-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6307LLU",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 80,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 37,
    "static_load_kN": 19.1,
    "fatigue_load_limit_kN": 1.47,
    "limiting_speed_rpm": 6000,
    "max_rpm": 6000,
    "weight_g": 457,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6307 carries bore code 07 = 35 mm. Outside diameter 80 mm and width 21 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6307LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At a 35 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6307-2RS-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 63xx medium section at 35 mm bore gains dynamic rating through larger rolling elements on a 80 mm OD; the penalty is mass and a lower limiting speed than the 6207 — do not specify it for speed-critical shafts.",
      "Heat is the enemy of the sealed 6307-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 6307-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6307-2RS-NTN-C3. No clearance suffix means normal CN clearance.",
      "The housing bore for the 80 mm OD should be round within IT7; an oval bore pinches the outer ring of 6307-2RS-NTN and shows up later as two-point loaded raceway wear.",
      "NTN catalogues the contact-sealed version as 6307LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 35 mm bore puts 6307 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6000 r/min the grease limiting speed for 6307 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 6307 at 37 kN dynamic (C) and 19.1 kN static (C0), 1.47 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 457 g, 6307 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 35×80×21 mm envelope of 6307 gives a D/d ratio of 2.29 and 22.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 37/19.1 kN load ratings, 1.47 kN fatigue load limit Cu NTN lists the grease limiting speed at 6000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 457 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6307LLU on the 35×80×21 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6307 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6307 is listed.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6307-2RS-NTN bearing?",
        "a": "A 6307-2RS-NTN deep-groove ball bearing has a 35 mm bore, 80 mm outer diameter and 21 mm width (1.378 × 3.15 × 0.827 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What internal clearance does 6307-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6307-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6307 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6307-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 35 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 6307?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6307LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×80×21 mm ISO 15 envelope."
      },
      {
        "q": "Is 6307LLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6307-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6307-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "307",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "307-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6307-llu",
      "6307llu",
      "6307-2RS",
      "6307-2rs",
      "6307LLU",
      "6307-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6307-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6307LLB",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 80,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 37,
    "static_load_kN": 19.1,
    "fatigue_load_limit_kN": 1.47,
    "limiting_speed_rpm": 7300,
    "max_rpm": 7300,
    "weight_g": 457,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6307 carries bore code 07 = 35 mm. Outside diameter 80 mm and width 21 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6307LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "fans and blowers",
      "electric motors",
      "centrifugal pumps",
      "small gearboxes"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Sizes around 35 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6307-RSR-NTN.",
      "The 63xx medium series gains rating at 35 mm bore through a 80 mm OD and 21 mm width; the heavier rolling elements also trade away some speed versus a 6207.",
      "RSR low-friction seals on 6307-RSR-NTN run faster than contact-seal 6307-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6307-2RS instead.",
      "The non-contact lip of 6307-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 35 mm bore position before relying on it as sealed-for-life.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6300-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Do not quieten a noisy bearing by preloading it: the 6300-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues this low-friction non-contact seal as 6307LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 35 mm bore puts 6307 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7300 r/min the grease limiting speed for 6307 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6307 at 37 kN dynamic (C) and 19.1 kN static (C0), 1.47 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 457 g, 6307 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 35×80×21 mm envelope of 6307 gives a D/d ratio of 2.29 and 22.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 37/19.1 kN load ratings, 1.47 kN fatigue load limit Cu NTN lists the grease limiting speed at 7300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 457 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6307LLB on the 35×80×21 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6307 in a rated drive.",
      "Standard catalogue stock of 6307 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Order the C3 internal-clearance version (6307 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6307-RSR-NTN bearing?",
        "a": "A 6307-RSR-NTN deep-groove ball bearing has a 35 mm bore, 80 mm outer diameter and 21 mm width (1.378 × 3.15 × 0.827 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6307 bore code work?",
        "a": "The last two digits of 6307 are bore code 07, giving 07 × 5 = 35 mm bore. The 80 mm outside diameter and 21 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the RSR suffix on 6307-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "What is the NTN suffix for a sealed 6307?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6307LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×80×21 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6307LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6307-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6307-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "307",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "307-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6307-llb",
      "6307llb",
      "6307-RSR",
      "6307-rsr",
      "6307LLB",
      "6307-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6307-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6307ZZ",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 80,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 37,
    "static_load_kN": 19.1,
    "fatigue_load_limit_kN": 1.47,
    "limiting_speed_rpm": 7300,
    "max_rpm": 7300,
    "weight_g": 457,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6307-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 07 by five gives the 35 mm bore; the 80 mm outside diameter and 21 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 35 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6307ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "fans and blowers",
      "electric motors",
      "centrifugal pumps",
      "small gearboxes"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At a 35 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6307-ZZ-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 63xx medium section at 35 mm bore gains dynamic rating through larger rolling elements on a 80 mm OD; the penalty is mass and a lower limiting speed than the 6207 — do not specify it for speed-critical shafts.",
      "ZZ shields are non-contact: 6307-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6307-2RS for that.",
      "Shielded 6307-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 21 mm-wide ring of 6307-ZZ-NTN drags the lip and overheats it.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues the shielded version as 6307ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 35 mm bore puts 6307 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7300 r/min the grease limiting speed for 6307 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6307 at 37 kN dynamic (C) and 19.1 kN static (C0), 1.47 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 457 g, 6307 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 35×80×21 mm envelope of 6307 gives a D/d ratio of 2.29 and 22.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 37/19.1 kN load ratings, 1.47 kN fatigue load limit Cu NTN lists the grease limiting speed at 7300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 457 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6307ZZ on the 35×80×21 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6307 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Order the C3 internal-clearance version (6307 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6307-ZZ-NTN bearing?",
        "a": "A 6307-ZZ-NTN deep-groove ball bearing has a 35 mm bore, 80 mm outer diameter and 21 mm width (1.378 × 3.15 × 0.827 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What lubrication does 6307-ZZ-NTN need?",
        "a": "6307-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "How does the 6307 bore code work?",
        "a": "The last two digits of 6307 are bore code 07, giving 07 × 5 = 35 mm bore. The 80 mm outside diameter and 21 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6307?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6307ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×80×21 mm ISO 15 envelope."
      },
      {
        "q": "Is 6307ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6307-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6307-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6307-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "307",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "307-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×80×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6307-zz",
      "6307zz",
      "6307-ZZ",
      "6307ZZ",
      "6307-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6407-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6407",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 61,
    "static_load_kN": 31,
    "fatigue_load_limit_kN": 2.43,
    "limiting_speed_rpm": 7800,
    "max_rpm": 7800,
    "weight_g": 952,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6407 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the heavy 64xx section (diameter series 4 of ISO 15), multiplying bore code 07 by five gives the 35 mm bore; the 100 mm outside diameter and 25 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 35 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "At a 35 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6407-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 64xx heavy section at 35 mm bore (100 mm OD) is built for high-load, lower-speed duty; specifying it in a high-rpm motor gives excess heat and short grease life — use 62/63 there.",
      "The open 6407-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 35×100×25 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6407-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 25 mm-wide ring of 6407-NTN drags the lip and overheats it.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 100 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6407-NTN.",
      "The open 6407 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 35 mm bore puts 6407 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7800 r/min the grease limiting speed for 6407 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6407 at 61 kN dynamic (C) and 31 kN static (C0), 2.43 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 952 g, 6407 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 35×100×25 mm envelope of 6407 gives a D/d ratio of 2.86 and 32.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 61/31 kN load ratings, 2.43 kN fatigue load limit Cu NTN lists the grease limiting speed at 7800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 952 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6407 on the 35×100×25 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6407 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Order the C3 internal-clearance version (6407 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6407-NTN bearing?",
        "a": "A 6407-NTN deep-groove ball bearing has a 35 mm bore, 100 mm outer diameter and 25 mm width (1.378 × 3.937 × 0.984 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What internal clearance does 6407-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6407-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6407 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6407-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 35 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN order number for an open 6407?",
        "a": "NTN lists the open 6407 under the bare designation 6407; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 35 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6407 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6407 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6407-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 35×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6407-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 35×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6407",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 35×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6407",
      "6407-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6407-ZZ",
    "brand": "NTN",
    "manufacturer_designation": "6407ZZ",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 35,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 61,
    "static_load_kN": 31,
    "fatigue_load_limit_kN": 2.43,
    "limiting_speed_rpm": 7800,
    "max_rpm": 7800,
    "weight_g": 952,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6400-series (diameter series 4 of ISO 15) the last two digits encode the bore: 6407 carries bore code 07 = 35 mm. Outside diameter 100 mm and width 25 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6407ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At a 35 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6407-ZZ; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 64xx heavy section at 35 mm bore (100 mm OD) is built for high-load, lower-speed duty; specifying it in a high-rpm motor gives excess heat and short grease life — use 62/63 there.",
      "ZZ shields are non-contact: 6407-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6407-2RS for that.",
      "Do not wash 6407-ZZ in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Never mix components between two 6407-ZZ units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 25 mm-wide ring of 6407-ZZ drags the lip and overheats it.",
      "NTN catalogues the shielded version as 6407ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 35 mm bore puts 6407 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7800 r/min the grease limiting speed for 6407 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6407 at 61 kN dynamic (C) and 31 kN static (C0), 2.43 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 952 g, 6407 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 35×100×25 mm envelope of 6407 gives a D/d ratio of 2.86 and 32.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 61/31 kN load ratings, 2.43 kN fatigue load limit Cu NTN lists the grease limiting speed at 7800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 952 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6407ZZ on the 35×100×25 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6407 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6407 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6407-ZZ bearing?",
        "a": "A 6407-ZZ deep-groove ball bearing has a 35 mm bore, 100 mm outer diameter and 25 mm width (1.378 × 3.937 × 0.984 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 6407 bore code work?",
        "a": "The last two digits of 6407 are bore code 07, giving 07 × 5 = 35 mm bore. The 100 mm outside diameter and 25 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the ZZ suffix on 6407-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "What is the NTN suffix for a sealed 6407?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6407ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 35×100×25 mm ISO 15 envelope."
      },
      {
        "q": "Is 6407ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6407-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 35×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6407-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 35×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6407",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 35×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=5",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6407-zz",
      "6407zz",
      "6407-ZZ",
      "6407ZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61808-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6808JR",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 52,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.65,
    "static_load_kN": 4.4,
    "fatigue_load_limit_kN": 0.29,
    "limiting_speed_rpm": 12000,
    "max_rpm": 12000,
    "weight_g": 33,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61808 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 08 by five gives the 40 mm bore; the 52 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 40 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "A 40 mm shaft for 61808 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "Only 6.0 mm of radial section separates bore and OD on the 618xx series at 40 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6208.",
      "The open 61808-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 40×52×7 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 61808-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 7 mm-wide ring of 61808-NTN drags the lip and overheats it.",
      "Do not quieten a noisy bearing by preloading it: the 61800-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "The open 61808 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 40 mm bore puts 61808 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN rates 61808 at 12000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the housing.",
      "NTN rates 61808 at 5.65 kN dynamic (C) and 4.4 kN static (C0), 0.29 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 33 g, 61808 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 40×52×7 mm envelope of 61808 gives a D/d ratio of 1.30 and only 6.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 5.65/4.4 kN load ratings, 0.29 kN fatigue load limit Cu NTN lists the grease limiting speed at 12000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 33 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6808JR on the 40×52×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61808 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61808 is listed.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61808-NTN bearing?",
        "a": "A 61808-NTN deep-groove ball bearing has a 40 mm bore, 52 mm outer diameter and 7 mm width (1.575 × 2.047 × 0.276 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What does no suffix on 61808 mean?",
        "a": "A bare 61808 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "How does the 61800 compare with other series at the same 40 mm bore?",
        "a": "618 is an extra-thin section: 52×7 mm, only 6.0 mm radial section at 40 mm bore, far smaller than a 6208, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "What is the NTN order number for an open 61808?",
        "a": "NTN lists the open 61808 under the bare designation 6808JR; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 40 mm bore envelope."
      },
      {
        "q": "Does NTN offer 61808 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6808JR is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61808-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6808jr",
      "61808",
      "6808JR",
      "61808-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61808-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6808JRLLU",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 52,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.65,
    "static_load_kN": 4.4,
    "fatigue_load_limit_kN": 0.29,
    "limiting_speed_rpm": 6700,
    "max_rpm": 6700,
    "weight_g": 33,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61808 carries bore code 08 = 40 mm. Outside diameter 52 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6808JRLLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Sizes around 40 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 61808-2RS-NTN.",
      "The 618xx thin section at 40 mm bore has only a 6.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6208.",
      "Contact seals add drag and heat: 61808-2RS-NTN runs slower and cooler-limited than the open 61808; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 61808-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Never mix components between two 61808-2RS-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "A 40 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues the contact-sealed version as 6808JRLLU (suffix RLLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 40 mm bore puts 61808 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6700 r/min the grease limiting speed for 61808 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 61808 at 5.65 kN dynamic (C) and 4.4 kN static (C0), 0.29 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 33 g, 61808 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 40×52×7 mm envelope of 61808 gives a D/d ratio of 1.30 and only 6.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 5.65/4.4 kN load ratings, 0.29 kN fatigue load limit Cu NTN lists the grease limiting speed at 6700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 33 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6808JRLLU on the 40×52×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61808 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61808 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61808-2RS-NTN bearing?",
        "a": "A 61808-2RS-NTN deep-groove ball bearing has a 40 mm bore, 52 mm outer diameter and 7 mm width (1.575 × 2.047 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What lubrication does 61808-2RS-NTN need?",
        "a": "61808-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61808 with a housing grease fitting instead."
      },
      {
        "q": "How does the 61808 bore code work?",
        "a": "The last two digits of 61808 are bore code 08, giving 08 × 5 = 40 mm bore. The 52 mm outside diameter and 7 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 61808?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6808JRLLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×52×7 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6808JRLLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61808-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61808-llu",
      "6808jrllu",
      "6808llu",
      "61808-2RS",
      "61808-2rs",
      "6808JRLLU",
      "61808-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61808-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6808JRLLB",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 52,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.65,
    "static_load_kN": 4.4,
    "fatigue_load_limit_kN": 0.29,
    "limiting_speed_rpm": 8000,
    "max_rpm": 8000,
    "weight_g": 33,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61808 carries bore code 08 = 40 mm. Outside diameter 52 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6808JRLLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "A 40 mm shaft for 61808 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "Only 6.0 mm of radial section separates bore and OD on the 618xx series at 40 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6208.",
      "RSR low-friction seals on 61808-RSR-NTN run faster than contact-seal 61808-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61808-2RS instead.",
      "The non-contact lip of 61808-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 40 mm bore position before relying on it as sealed-for-life.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 52 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61808-RSR-NTN.",
      "Shaft and housing fillets must clear the bearing chamfer so the 7 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues this low-friction non-contact seal as 6808JRLLB (suffix RLLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 40 mm bore puts 61808 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8000 r/min the grease limiting speed for 61808 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61808 at 5.65 kN dynamic (C) and 4.4 kN static (C0), 0.29 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 33 g, 61808 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 40×52×7 mm envelope of 61808 gives a D/d ratio of 1.30 and only 6.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 5.65/4.4 kN load ratings, 0.29 kN fatigue load limit Cu NTN lists the grease limiting speed at 8000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 33 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6808JRLLB on the 40×52×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61808 in a rated drive.",
      "Standard catalogue stock of 61808 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Order the C3 internal-clearance version (61808 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61808-RSR-NTN bearing?",
        "a": "A 61808-RSR-NTN deep-groove ball bearing has a 40 mm bore, 52 mm outer diameter and 7 mm width (1.575 × 2.047 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 61800 compare with other series at the same 40 mm bore?",
        "a": "618 is an extra-thin section: 52×7 mm, only 6.0 mm radial section at 40 mm bore, far smaller than a 6208, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "Are 61808 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61808 uses the same ISO 15 envelope (40×52×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61808?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6808JRLLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×52×7 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61808 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6808JRLLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61808-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61808-llb",
      "6808jrllb",
      "6808llb",
      "61808-RSR",
      "61808-rsr",
      "6808JRLLB",
      "61808-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61808-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6808JRZZ",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 52,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.65,
    "static_load_kN": 4.4,
    "fatigue_load_limit_kN": 0.29,
    "limiting_speed_rpm": 8000,
    "max_rpm": 8000,
    "weight_g": 33,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61808 carries bore code 08 = 40 mm. Outside diameter 52 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6808JRZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "A 40 mm shaft for 61808 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "Only 6.0 mm of radial section separates bore and OD on the 618xx series at 40 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6208.",
      "ZZ shields are non-contact: 61808-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61808-2RS for that.",
      "Shielded 61808-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Never mix components between two 61808-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues the shielded version as 6808JRZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 40 mm bore puts 61808 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8000 r/min the grease limiting speed for 61808 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61808 at 5.65 kN dynamic (C) and 4.4 kN static (C0), 0.29 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 33 g, 61808 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 40×52×7 mm envelope of 61808 gives a D/d ratio of 1.30 and only 6.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 5.65/4.4 kN load ratings, 0.29 kN fatigue load limit Cu NTN lists the grease limiting speed at 8000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 33 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6808JRZZ on the 40×52×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61808 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61808-ZZ-NTN bearing?",
        "a": "A 61808-ZZ-NTN deep-groove ball bearing has a 40 mm bore, 52 mm outer diameter and 7 mm width (1.575 × 2.047 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 61800 compare with other series at the same 40 mm bore?",
        "a": "618 is an extra-thin section: 52×7 mm, only 6.0 mm radial section at 40 mm bore, far smaller than a 6208, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "Are 61808 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61808 uses the same ISO 15 envelope (40×52×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61808?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6808JRZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×52×7 mm ISO 15 envelope."
      },
      {
        "q": "Is 6808JRZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61808-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61808-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×52×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61808-zz",
      "6808jrzz",
      "6808zz",
      "61808-ZZ",
      "6808JRZZ",
      "61808-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61908-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6908",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 62,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 13.5,
    "static_load_kN": 8.9,
    "fatigue_load_limit_kN": 0.65,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "weight_g": 110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61908 carries bore code 08 = 40 mm. Outside diameter 62 mm and width 12 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Sizes around 40 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 61908-NTN.",
      "The 619xx thin section (11.0 mm section height at 40 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "The open 61908-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 40×62×12 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 61900-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61908 units.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61900-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Measure the shaft, do not trust the drawing: a 40 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61908-NTN.",
      "The open 61908 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 40 mm bore puts 61908 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 11000 r/min the grease limiting speed for 61908 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61908 at 13.5 kN dynamic (C) and 8.9 kN static (C0), 0.65 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 110 g, 61908 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 40×62×12 mm envelope of 61908 gives a D/d ratio of 1.55 and 11.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 13.5/8.9 kN load ratings, 0.65 kN fatigue load limit Cu NTN lists the grease limiting speed at 11000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 110 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6908 on the 40×62×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61908 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61908-NTN bearing?",
        "a": "A 61908-NTN deep-groove ball bearing has a 40 mm bore, 62 mm outer diameter and 12 mm width (1.575 × 2.441 × 0.472 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 61908 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61908 uses the same ISO 15 envelope (40×62×12 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 61908-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61908-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61908 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 61908?",
        "a": "NTN lists the open 61908 under the bare designation 6908; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 40 mm bore envelope."
      },
      {
        "q": "Does NTN offer 61908 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6908 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61908-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61908-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6908",
      "61908",
      "61908-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61908-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6908LLU",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 62,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 13.5,
    "static_load_kN": 8.9,
    "fatigue_load_limit_kN": 0.65,
    "limiting_speed_rpm": 6300,
    "max_rpm": 6300,
    "weight_g": 110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61908-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 08 by five gives the 40 mm bore; the 62 mm outside diameter and 12 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 40 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6908LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "A 40 mm shaft for 61908 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 619xx thin section (11.0 mm section height at 40 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "Contact seals add drag and heat: 61908-2RS-NTN runs slower and cooler-limited than the open 61908; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 61908-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "A 40 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Vibration during standstill brinells the raceways of a 40 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues the contact-sealed version as 6908LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 40 mm bore puts 61908 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6300 r/min the grease limiting speed for 61908 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 61908 at 13.5 kN dynamic (C) and 8.9 kN static (C0), 0.65 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 110 g, 61908 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 40×62×12 mm envelope of 61908 gives a D/d ratio of 1.55 and 11.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 13.5/8.9 kN load ratings, 0.65 kN fatigue load limit Cu NTN lists the grease limiting speed at 6300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 110 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6908LLU on the 40×62×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61908 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61908 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61908-2RS-NTN bearing?",
        "a": "A 61908-2RS-NTN deep-groove ball bearing has a 40 mm bore, 62 mm outer diameter and 12 mm width (1.575 × 2.441 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 61900 compare with other series at the same 40 mm bore?",
        "a": "619 is a thin section one step above 618: 62×12 mm with an 11.0 mm radial section at 40 mm bore; a 6208 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "Are 61908 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61908 uses the same ISO 15 envelope (40×62×12 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61908?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6908LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×62×12 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61908 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6908LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61908-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61908-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61908-llu",
      "6908llu",
      "61908-2RS",
      "61908-2rs",
      "6908LLU",
      "61908-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61908-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6908LLB",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 62,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 13.5,
    "static_load_kN": 8.9,
    "fatigue_load_limit_kN": 0.65,
    "limiting_speed_rpm": 7500,
    "max_rpm": 7500,
    "weight_g": 110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61908-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 08 by five gives the 40 mm bore; the 62 mm outside diameter and 12 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 40 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6908LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Sizes around 40 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 61908-RSR-NTN.",
      "The 619xx thin section (11.0 mm section height at 40 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "The low-drag lip of 61908-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 61908-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 40 mm bore position before relying on it as sealed-for-life.",
      "The housing bore for the 62 mm OD should be round within IT7; an oval bore pinches the outer ring of 61908-RSR-NTN and shows up later as two-point loaded raceway wear.",
      "Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues this low-friction non-contact seal as 6908LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 40 mm bore puts 61908 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7500 r/min the grease limiting speed for 61908 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61908 at 13.5 kN dynamic (C) and 8.9 kN static (C0), 0.65 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 110 g, 61908 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 40×62×12 mm envelope of 61908 gives a D/d ratio of 1.55 and 11.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 13.5/8.9 kN load ratings, 0.65 kN fatigue load limit Cu NTN lists the grease limiting speed at 7500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 110 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6908LLB on the 40×62×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61908 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61908 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61908-RSR-NTN bearing?",
        "a": "A 61908-RSR-NTN deep-groove ball bearing has a 40 mm bore, 62 mm outer diameter and 12 mm width (1.575 × 2.441 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 61908 bore code work?",
        "a": "The last two digits of 61908 are bore code 08, giving 08 × 5 = 40 mm bore. The 62 mm outside diameter and 12 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the RSR suffix on 61908-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "What is the NTN suffix for a sealed 61908?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6908LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×62×12 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61908 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6908LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61908-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61908-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61908-llb",
      "6908llb",
      "61908-RSR",
      "61908-rsr",
      "6908LLB",
      "61908-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61908-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6908ZZ",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 62,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 13.5,
    "static_load_kN": 8.9,
    "fatigue_load_limit_kN": 0.65,
    "limiting_speed_rpm": 7500,
    "max_rpm": 7500,
    "weight_g": 110,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61908-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 08 by five gives the 40 mm bore; the 62 mm outside diameter and 12 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 40 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6908ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "A 40 mm shaft for 61908 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 619xx thin section at 40 mm bore (11.0 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "ZZ shields are non-contact: 61908-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61908-2RS for that.",
      "Do not wash 61908-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61908-ZZ-NTN-C3. No clearance suffix means normal CN clearance.",
      "The housing bore for the 62 mm OD should be round within IT7; an oval bore pinches the outer ring of 61908-ZZ-NTN and shows up later as two-point loaded raceway wear.",
      "NTN catalogues the shielded version as 6908ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 40 mm bore puts 61908 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7500 r/min the grease limiting speed for 61908 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61908 at 13.5 kN dynamic (C) and 8.9 kN static (C0), 0.65 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 110 g, 61908 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 40×62×12 mm envelope of 61908 gives a D/d ratio of 1.55 and 11.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 13.5/8.9 kN load ratings, 0.65 kN fatigue load limit Cu NTN lists the grease limiting speed at 7500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 110 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6908ZZ on the 40×62×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61908 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Order the C3 internal-clearance version (61908 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61908-ZZ-NTN bearing?",
        "a": "A 61908-ZZ-NTN deep-groove ball bearing has a 40 mm bore, 62 mm outer diameter and 12 mm width (1.575 × 2.441 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What lubrication does 61908-ZZ-NTN need?",
        "a": "61908-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "How does the 61908 bore code work?",
        "a": "The last two digits of 61908 are bore code 08, giving 08 × 5 = 40 mm bore. The 62 mm outside diameter and 12 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 61908?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6908ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×62×12 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6908ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61908-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61908-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61908-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×62×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61908-zz",
      "6908zz",
      "61908-ZZ",
      "6908ZZ",
      "61908-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "16008-NTN",
    "brand": "NTN",
    "manufacturer_designation": "16008",
    "series": "16000-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 68,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 14,
    "static_load_kN": 9.65,
    "fatigue_load_limit_kN": 0.69,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "weight_g": 125,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 16000-series (the narrow extra-light section of ISO 15) the last two digits encode the bore: 16008 carries bore code 08 = 40 mm. Outside diameter 68 mm and width 9 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers",
      "electric motors"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Sizes around 40 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 16008-NTN.",
      "Because the 160xx narrow section shares the 68 mm OD of the 6008 at 40 mm bore but is only 9 mm wide, a housing machined for the wider bearing needs a spacer or relocated circlip — never assume width interchangeability.",
      "The open 16008-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 40×68×9 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 16008-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "The housing bore for the 68 mm OD should be round within IT7; an oval bore pinches the outer ring of 16008-NTN and shows up later as two-point loaded raceway wear.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "The open 16008 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 40 mm bore puts 16008 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 10000 r/min the grease limiting speed for 16008 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 16008 at 14 kN dynamic (C) and 9.65 kN static (C0), 0.69 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 125 g, 16008 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 40×68×9 mm envelope of 16008 gives a D/d ratio of 1.70 and 14.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 14/9.65 kN load ratings, 0.69 kN fatigue load limit Cu NTN lists the grease limiting speed at 10000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 125 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 16008 on the 40×68×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 16008 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 16008 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 16008-NTN bearing?",
        "a": "A 16008-NTN deep-groove ball bearing has a 40 mm bore, 68 mm outer diameter and 9 mm width (1.575 × 2.677 × 0.354 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 16008 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 16008 uses the same ISO 15 envelope (40×68×9 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 16008-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 16008-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 16008 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 16008?",
        "a": "NTN lists the open 16008 under the bare designation 16008; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 40 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 16008?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "16008",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 40×68×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "16008",
      "16008-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6008-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6008",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 68,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 18.6,
    "static_load_kN": 11.5,
    "fatigue_load_limit_kN": 0.89,
    "limiting_speed_rpm": 10000,
    "max_rpm": 10000,
    "weight_g": 190,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6008 carries bore code 08 = 40 mm. Outside diameter 68 mm and width 15 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "At a 40 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6008-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 60xx extra-light section at 40 mm bore uses a smaller 68 mm OD than a 6208; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "Storage matters for open bearings: 6008-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 6000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6008 units.",
      "Shaft and housing fillets must clear the bearing chamfer so the 15 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Never mix components between two 6008-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "The open 6008 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 40 mm bore puts 6008 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 10000 r/min the grease limiting speed for 6008 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 18.6 kN dynamic load rating (C) and 11.5 kN static (C0), 0.89 kN fatigue load limit Cu, 6008 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 190 g, 6008 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 40×68×15 mm envelope of 6008 gives a D/d ratio of 1.70 and 14.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 18.6/11.5 kN load ratings, 0.89 kN fatigue load limit Cu NTN lists the grease limiting speed at 10000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 190 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6008 on the 40×68×15 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6008 in a rated drive.",
      "Order the C3 internal-clearance version (6008 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6008 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6008-NTN bearing?",
        "a": "A 6008-NTN deep-groove ball bearing has a 40 mm bore, 68 mm outer diameter and 15 mm width (1.575 × 2.677 × 0.591 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How should 6008-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 40 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6008-NTN need?",
        "a": "The open 6008-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "What is the NTN order number for an open 6008?",
        "a": "NTN lists the open 6008 under the bare designation 6008; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 40 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6008?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6008-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6008-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6008-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6008",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6008",
      "6008-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6008-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6008LLU",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 68,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 18.6,
    "static_load_kN": 11.5,
    "fatigue_load_limit_kN": 0.89,
    "limiting_speed_rpm": 6100,
    "max_rpm": 6100,
    "weight_g": 190,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6008-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 08 by five gives the 40 mm bore; the 68 mm outside diameter and 15 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 40 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6008LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers",
      "electric motors"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "A 40 mm shaft for 6008 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 60xx extra-light section at 40 mm bore uses a smaller 68 mm OD than a 6208; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "Contact seals add drag and heat: 6008-2RS-NTN runs slower and cooler-limited than the open 6008; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 6008-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6000-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues the contact-sealed version as 6008LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 40 mm bore puts 6008 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6100 r/min the grease limiting speed for 6008 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "At 18.6 kN dynamic load rating (C) and 11.5 kN static (C0), 0.89 kN fatigue load limit Cu, 6008 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 190 g, 6008 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 40×68×15 mm envelope of 6008 gives a D/d ratio of 1.70 and 14.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 18.6/11.5 kN load ratings, 0.89 kN fatigue load limit Cu NTN lists the grease limiting speed at 6100 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 190 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6008LLU on the 40×68×15 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6008 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Standard catalogue stock of 6008 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6008-2RS-NTN bearing?",
        "a": "A 6008-2RS-NTN deep-groove ball bearing has a 40 mm bore, 68 mm outer diameter and 15 mm width (1.575 × 2.677 × 0.591 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How should 6008-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 40 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6008-2RS-NTN need?",
        "a": "6008-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6008 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 6008?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6008LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×68×15 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6008LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6008-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6008-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6008-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6008",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6008-llu",
      "6008llu",
      "6008-2RS",
      "6008-2rs",
      "6008LLU",
      "6008-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6008-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6008LLB",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 68,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 18.6,
    "static_load_kN": 11.5,
    "fatigue_load_limit_kN": 0.89,
    "limiting_speed_rpm": 7300,
    "max_rpm": 7300,
    "weight_g": 190,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6008-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 08 by five gives the 40 mm bore; the 68 mm outside diameter and 15 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 40 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6008LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers",
      "electric motors"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "At a 40 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6008-RSR-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 60xx extra-light section at 40 mm bore uses a smaller 68 mm OD than a 6208; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "RSR low-friction seals on 6008-RSR-NTN run faster than contact-seal 6008-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6008-2RS instead.",
      "The low-drag lip of 6008-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 15 mm-wide ring of 6008-RSR-NTN drags the lip and overheats it.",
      "Never mix components between two 6008-RSR-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues this low-friction non-contact seal as 6008LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 40 mm bore puts 6008 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7300 r/min the grease limiting speed for 6008 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 18.6 kN dynamic load rating (C) and 11.5 kN static (C0), 0.89 kN fatigue load limit Cu, 6008 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 190 g, 6008 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 40×68×15 mm envelope of 6008 gives a D/d ratio of 1.70 and 14.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 18.6/11.5 kN load ratings, 0.89 kN fatigue load limit Cu NTN lists the grease limiting speed at 7300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 190 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6008LLB on the 40×68×15 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6008 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Standard catalogue stock of 6008 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6008-RSR-NTN bearing?",
        "a": "A 6008-RSR-NTN deep-groove ball bearing has a 40 mm bore, 68 mm outer diameter and 15 mm width (1.575 × 2.677 × 0.591 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6000 compare with other series at the same 40 mm bore?",
        "a": "The second digit is the diameter series: 60 is the smallest standard section (68×15 mm, 14.0 mm radial section) at 40 mm bore — below 62/63/64 in load capacity, for light loads in compact spaces."
      },
      {
        "q": "Are 6008 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6008 uses the same ISO 15 envelope (40×68×15 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6008?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6008LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×68×15 mm ISO 15 envelope."
      },
      {
        "q": "Is 6008LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6008-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6008-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6008-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6008",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6008-llb",
      "6008llb",
      "6008-RSR",
      "6008-rsr",
      "6008LLB",
      "6008-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6008-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6008ZZ",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 68,
    "B_mm": 15,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 18.6,
    "static_load_kN": 11.5,
    "fatigue_load_limit_kN": 0.89,
    "limiting_speed_rpm": 7300,
    "max_rpm": 7300,
    "weight_g": 190,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6008-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 08 by five gives the 40 mm bore; the 68 mm outside diameter and 15 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 40 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6008ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "At a 40 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6008-ZZ-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "Choosing the 60xx extra-light section saves radial space at 40 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6208 before committing to the smaller envelope.",
      "Do not wash 6008-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6008-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6000-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Vibration during standstill brinells the raceways of a 40 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues the shielded version as 6008ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 40 mm bore puts 6008 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7300 r/min the grease limiting speed for 6008 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 18.6 kN dynamic load rating (C) and 11.5 kN static (C0), 0.89 kN fatigue load limit Cu, 6008 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 190 g, 6008 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 40×68×15 mm envelope of 6008 gives a D/d ratio of 1.70 and 14.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 18.6/11.5 kN load ratings, 0.89 kN fatigue load limit Cu NTN lists the grease limiting speed at 7300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 190 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6008ZZ on the 40×68×15 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6008 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6008-ZZ-NTN bearing?",
        "a": "A 6008-ZZ-NTN deep-groove ball bearing has a 40 mm bore, 68 mm outer diameter and 15 mm width (1.575 × 2.677 × 0.591 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What lubrication does 6008-ZZ-NTN need?",
        "a": "6008-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "How does the 6008 bore code work?",
        "a": "The last two digits of 6008 are bore code 08, giving 08 × 5 = 40 mm bore. The 68 mm outside diameter and 15 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6008?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6008ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×68×15 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6008ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6008-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6008-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6008-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6008-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6008",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×68×15 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6008-zz",
      "6008zz",
      "6008-ZZ",
      "6008ZZ",
      "6008-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6208-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6208",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 32.5,
    "static_load_kN": 17.8,
    "fatigue_load_limit_kN": 1.24,
    "limiting_speed_rpm": 8700,
    "max_rpm": 8700,
    "weight_g": 366,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6208 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 08 by five gives the 40 mm bore; the 80 mm outside diameter and 18 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 40 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "electric motors",
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At a 40 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6208-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 62xx light series is the default general-purpose section at 40 mm bore; before upgrading to a 6308 for extra capacity, confirm the housing accepts a 80 mm OD and 18 mm width — it is not a drop-in swap.",
      "Storage matters for open bearings: 6208-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 6200-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6208 units.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6200-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "The open 6208 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 40 mm bore puts 6208 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8700 r/min the grease limiting speed for 6208 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 32.5 kN dynamic load rating (C) and 17.8 kN static (C0), 1.24 kN fatigue load limit Cu, 6208 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 366 g, 6208 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 40×80×18 mm envelope of 6208 gives a D/d ratio of 2.00 and 20.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 32.5/17.8 kN load ratings, 1.24 kN fatigue load limit Cu NTN lists the grease limiting speed at 8700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 366 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6208 on the 40×80×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6208 in a rated drive.",
      "Standard catalogue stock of 6208 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6208-NTN bearing?",
        "a": "A 6208-NTN deep-groove ball bearing has a 40 mm bore, 80 mm outer diameter and 18 mm width (1.575 × 3.15 × 0.709 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What does no suffix on 6208 mean?",
        "a": "A bare 6208 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "How does the 6200 compare with other series at the same 40 mm bore?",
        "a": "The '2' is the light diameter series: 80×18 mm with a 20.0 mm radial section at 40 mm bore. A 6308 on the same bore is larger and higher-rated; a 6008 is smaller and lower-rated."
      },
      {
        "q": "What is the NTN order number for an open 6208?",
        "a": "NTN lists the open 6208 under the bare designation 6208; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 40 mm bore envelope."
      },
      {
        "q": "Is 6208 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6208-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6208-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6208-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6208",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "208",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "208-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6208",
      "6208-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6208-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6208LLU",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 32.5,
    "static_load_kN": 17.8,
    "fatigue_load_limit_kN": 1.24,
    "limiting_speed_rpm": 5600,
    "max_rpm": 5600,
    "weight_g": 366,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6208 carries bore code 08 = 40 mm. Outside diameter 80 mm and width 18 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6208LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "fans and blowers",
      "electric motors",
      "centrifugal pumps",
      "small gearboxes"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Sizes around 40 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6208-2RS-NTN.",
      "At 40 mm bore the 62xx light series is the workhorse section; its 80×18 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "Contact seals add drag and heat: 6208-2RS-NTN runs slower and cooler-limited than the open 6208; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 6208-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 18 mm-wide ring of 6208-2RS-NTN drags the lip and overheats it.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 80 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6208-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6208LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 40 mm bore puts 6208 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5600 r/min the grease limiting speed for 6208 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "At 32.5 kN dynamic load rating (C) and 17.8 kN static (C0), 1.24 kN fatigue load limit Cu, 6208 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 366 g, 6208 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 40×80×18 mm envelope of 6208 gives a D/d ratio of 2.00 and 20.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 32.5/17.8 kN load ratings, 1.24 kN fatigue load limit Cu NTN lists the grease limiting speed at 5600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 366 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6208LLU on the 40×80×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6208 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Order the C3 internal-clearance version (6208 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6208-2RS-NTN bearing?",
        "a": "A 6208-2RS-NTN deep-groove ball bearing has a 40 mm bore, 80 mm outer diameter and 18 mm width (1.575 × 3.15 × 0.709 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What internal clearance does 6208-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6208-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6208 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6208-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 40 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 6208?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6208LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×80×18 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6208LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6208-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6208-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6208-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6208",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "208",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "208-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6208-llu",
      "6208llu",
      "6208-2RS",
      "6208-2rs",
      "6208LLU",
      "6208-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6208-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6208LLB",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 32.5,
    "static_load_kN": 17.8,
    "fatigue_load_limit_kN": 1.24,
    "limiting_speed_rpm": 6700,
    "max_rpm": 6700,
    "weight_g": 366,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6208 carries bore code 08 = 40 mm. Outside diameter 80 mm and width 18 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6208LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "A 40 mm shaft for 6208 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 62xx light series is the default general-purpose section at 40 mm bore; before upgrading to a 6308 for extra capacity, confirm the housing accepts a 80 mm OD and 18 mm width — it is not a drop-in swap.",
      "RSR low-friction seals on 6208-RSR-NTN run faster than contact-seal 6208-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6208-2RS instead.",
      "The non-contact lip of 6208-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 40 mm bore position before relying on it as sealed-for-life.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 18 mm-wide ring of 6208-RSR-NTN drags the lip and overheats it.",
      "Measure the shaft, do not trust the drawing: a 40 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6208-RSR-NTN.",
      "NTN catalogues this low-friction non-contact seal as 6208LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 40 mm bore puts 6208 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6700 r/min the grease limiting speed for 6208 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 32.5 kN dynamic load rating (C) and 17.8 kN static (C0), 1.24 kN fatigue load limit Cu, 6208 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 366 g, 6208 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 40×80×18 mm envelope of 6208 gives a D/d ratio of 2.00 and 20.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 32.5/17.8 kN load ratings, 1.24 kN fatigue load limit Cu NTN lists the grease limiting speed at 6700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 366 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6208LLB on the 40×80×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6208 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6208-RSR-NTN bearing?",
        "a": "A 6208-RSR-NTN deep-groove ball bearing has a 40 mm bore, 80 mm outer diameter and 18 mm width (1.575 × 3.15 × 0.709 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6200 compare with other series at the same 40 mm bore?",
        "a": "The '2' is the light diameter series: 80×18 mm with a 20.0 mm radial section at 40 mm bore. A 6308 on the same bore is larger and higher-rated; a 6008 is smaller and lower-rated."
      },
      {
        "q": "Are 6208 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6208 uses the same ISO 15 envelope (40×80×18 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6208?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6208LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×80×18 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6208 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6208LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6208-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6208-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6208-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6208",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "208",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "208-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6208-llb",
      "6208llb",
      "6208-RSR",
      "6208-rsr",
      "6208LLB",
      "6208-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6208-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6208ZZ",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 80,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 32.5,
    "static_load_kN": 17.8,
    "fatigue_load_limit_kN": 1.24,
    "limiting_speed_rpm": 6700,
    "max_rpm": 6700,
    "weight_g": 366,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6208 carries bore code 08 = 40 mm. Outside diameter 80 mm and width 18 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6208ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "electric motors",
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "At a 40 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6208-ZZ-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "At 40 mm bore the 62xx light series is the workhorse section; its 80×18 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "Do not wash 6208-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6208-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Vibration during standstill brinells the raceways of a 40 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 80 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6208-ZZ-NTN.",
      "NTN catalogues the shielded version as 6208ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 40 mm bore puts 6208 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6700 r/min the grease limiting speed for 6208 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 32.5 kN dynamic load rating (C) and 17.8 kN static (C0), 1.24 kN fatigue load limit Cu, 6208 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 366 g, 6208 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 40×80×18 mm envelope of 6208 gives a D/d ratio of 2.00 and 20.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 32.5/17.8 kN load ratings, 1.24 kN fatigue load limit Cu NTN lists the grease limiting speed at 6700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 366 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6208ZZ on the 40×80×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6208 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Standard catalogue stock of 6208 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6208-ZZ-NTN bearing?",
        "a": "A 6208-ZZ-NTN deep-groove ball bearing has a 40 mm bore, 80 mm outer diameter and 18 mm width (1.575 × 3.15 × 0.709 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How should 6208-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 40 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6208-ZZ-NTN need?",
        "a": "6208-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "What is the NTN suffix for a sealed 6208?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6208ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×80×18 mm ISO 15 envelope."
      },
      {
        "q": "Is 6208ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6208-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6208-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6208-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6208-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6208",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "208",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "208-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×80×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6208-zz",
      "6208zz",
      "6208-ZZ",
      "6208ZZ",
      "6208-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6308-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6308",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 90,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 45,
    "static_load_kN": 24,
    "fatigue_load_limit_kN": 1.83,
    "limiting_speed_rpm": 7800,
    "max_rpm": 7800,
    "weight_g": 630,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6308 carries bore code 08 = 40 mm. Outside diameter 90 mm and width 23 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Sizes around 40 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6308-NTN.",
      "The 63xx medium section at 40 mm bore gains dynamic rating through larger rolling elements on a 90 mm OD; the penalty is mass and a lower limiting speed than the 6208 — do not specify it for speed-critical shafts.",
      "Storage matters for open bearings: 6308-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 6300-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6308 units.",
      "Never mix components between two 6308-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "A 40 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "The open 6308 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 40 mm bore puts 6308 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7800 r/min the grease limiting speed for 6308 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6308 at 45 kN dynamic (C) and 24 kN static (C0), 1.83 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 630 g, 6308 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 40×90×23 mm envelope of 6308 gives a D/d ratio of 2.25 and 25.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 45/24 kN load ratings, 1.83 kN fatigue load limit Cu NTN lists the grease limiting speed at 7800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 630 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6308 on the 40×90×23 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6308 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Order the C3 internal-clearance version (6308 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6308-NTN bearing?",
        "a": "A 6308-NTN deep-groove ball bearing has a 40 mm bore, 90 mm outer diameter and 23 mm width (1.575 × 3.543 × 0.906 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6300 compare with other series at the same 40 mm bore?",
        "a": "The '3' is the medium diameter series: 90×23 mm, 25.0 mm radial section at 40 mm bore, carrying more load than a 6208 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "Are 6308 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6308 uses the same ISO 15 envelope (40×90×23 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 6308?",
        "a": "NTN lists the open 6308 under the bare designation 6308; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 40 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6308 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6308 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6308-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "308",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "308-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6308",
      "6308-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6308-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6308LLU",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 90,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 45,
    "static_load_kN": 24,
    "fatigue_load_limit_kN": 1.83,
    "limiting_speed_rpm": 5300,
    "max_rpm": 5300,
    "weight_g": 630,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6308 carries bore code 08 = 40 mm. Outside diameter 90 mm and width 23 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6308LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "At a 40 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6308-2RS-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 63xx medium series gains rating at 40 mm bore through a 90 mm OD and 23 mm width; the heavier rolling elements also trade away some speed versus a 6208.",
      "Heat is the enemy of the sealed 6308-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 6308-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "A 40 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Do not quieten a noisy bearing by preloading it: the 6300-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues the contact-sealed version as 6308LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 40 mm bore puts 6308 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5300 r/min the grease limiting speed for 6308 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 6308 at 45 kN dynamic (C) and 24 kN static (C0), 1.83 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 630 g, 6308 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 40×90×23 mm envelope of 6308 gives a D/d ratio of 2.25 and 25.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 45/24 kN load ratings, 1.83 kN fatigue load limit Cu NTN lists the grease limiting speed at 5300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 630 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6308LLU on the 40×90×23 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6308 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Order the C3 internal-clearance version (6308 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6308-2RS-NTN bearing?",
        "a": "A 6308-2RS-NTN deep-groove ball bearing has a 40 mm bore, 90 mm outer diameter and 23 mm width (1.575 × 3.543 × 0.906 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 6300 compare with other series at the same 40 mm bore?",
        "a": "The '3' is the medium diameter series: 90×23 mm, 25.0 mm radial section at 40 mm bore, carrying more load than a 6208 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "Are 6308 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6308 uses the same ISO 15 envelope (40×90×23 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6308?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6308LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×90×23 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6308LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6308-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "308",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "308-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6308-llu",
      "6308llu",
      "6308-2RS",
      "6308-2rs",
      "6308LLU",
      "6308-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6308-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6308LLB",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 90,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 45,
    "static_load_kN": 24,
    "fatigue_load_limit_kN": 1.83,
    "limiting_speed_rpm": 6400,
    "max_rpm": 6400,
    "weight_g": 630,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6308 carries bore code 08 = 40 mm. Outside diameter 90 mm and width 23 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6308LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "electric motors",
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "A 40 mm shaft for 6308 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 63xx medium series gains rating at 40 mm bore through a 90 mm OD and 23 mm width; the heavier rolling elements also trade away some speed versus a 6208.",
      "RSR low-friction seals on 6308-RSR-NTN run faster than contact-seal 6308-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6308-2RS instead.",
      "The non-contact lip of 6308-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 40 mm bore position before relying on it as sealed-for-life.",
      "The housing bore for the 90 mm OD should be round within IT7; an oval bore pinches the outer ring of 6308-RSR-NTN and shows up later as two-point loaded raceway wear.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6308-RSR-NTN-C3. No clearance suffix means normal CN clearance.",
      "NTN catalogues this low-friction non-contact seal as 6308LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 40 mm bore puts 6308 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6400 r/min the grease limiting speed for 6308 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6308 at 45 kN dynamic (C) and 24 kN static (C0), 1.83 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 630 g, 6308 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 40×90×23 mm envelope of 6308 gives a D/d ratio of 2.25 and 25.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 45/24 kN load ratings, 1.83 kN fatigue load limit Cu NTN lists the grease limiting speed at 6400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 630 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6308LLB on the 40×90×23 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6308 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6308-RSR-NTN bearing?",
        "a": "A 6308-RSR-NTN deep-groove ball bearing has a 40 mm bore, 90 mm outer diameter and 23 mm width (1.575 × 3.543 × 0.906 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "Are 6308 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6308 uses the same ISO 15 envelope (40×90×23 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 6308-RSR-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6308-RSR-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6308 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 6308?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6308LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×90×23 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6308LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6308-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "308",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "308-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6308-llb",
      "6308llb",
      "6308-RSR",
      "6308-rsr",
      "6308LLB",
      "6308-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6308-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6308ZZ",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 90,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 45,
    "static_load_kN": 24,
    "fatigue_load_limit_kN": 1.83,
    "limiting_speed_rpm": 6400,
    "max_rpm": 6400,
    "weight_g": 630,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6308 carries bore code 08 = 40 mm. Outside diameter 90 mm and width 23 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6308ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "A 40 mm shaft for 6308 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 63xx medium section at 40 mm bore gains dynamic rating through larger rolling elements on a 90 mm OD; the penalty is mass and a lower limiting speed than the 6208 — do not specify it for speed-critical shafts.",
      "Do not wash 6308-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6308-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Vibration during standstill brinells the raceways of a 40 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 23 mm-wide ring of 6308-ZZ-NTN drags the lip and overheats it.",
      "NTN catalogues the shielded version as 6308ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 40 mm bore puts 6308 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6400 r/min the grease limiting speed for 6308 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6308 at 45 kN dynamic (C) and 24 kN static (C0), 1.83 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 630 g, 6308 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 40×90×23 mm envelope of 6308 gives a D/d ratio of 2.25 and 25.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 45/24 kN load ratings, 1.83 kN fatigue load limit Cu NTN lists the grease limiting speed at 6400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 630 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6308ZZ on the 40×90×23 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6308 in a rated drive.",
      "Standard catalogue stock of 6308 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6308 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6308-ZZ-NTN bearing?",
        "a": "A 6308-ZZ-NTN deep-groove ball bearing has a 40 mm bore, 90 mm outer diameter and 23 mm width (1.575 × 3.543 × 0.906 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "Are 6308 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6308 uses the same ISO 15 envelope (40×90×23 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 6308-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6308-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6308 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 6308?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6308ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×90×23 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6308 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6308ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6308-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6308-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "308",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "308-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×90×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6308-zz",
      "6308zz",
      "6308-ZZ",
      "6308ZZ",
      "6308-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6408-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6408",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 110,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 70.5,
    "static_load_kN": 36.5,
    "fatigue_load_limit_kN": 2.85,
    "limiting_speed_rpm": 7000,
    "max_rpm": 7000,
    "weight_g": 1230,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6400-series (diameter series 4 of ISO 15) the last two digits encode the bore: 6408 carries bore code 08 = 40 mm. Outside diameter 110 mm and width 27 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "At a 40 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6408-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 64xx heavy section at 40 mm bore exists for high radial load at moderate rpm; its 110 mm OD and 27 mm width demand a larger housing, and grease life at motor speeds is short — treat it as a low-speed, high-load choice.",
      "Storage matters for open bearings: 6408-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 6400-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6408 units.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 27 mm-wide ring of 6408-NTN drags the lip and overheats it.",
      "Vibration during standstill brinells the raceways of a 40 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "The open 6408 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 40 mm bore puts 6408 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7000 r/min the grease limiting speed for 6408 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 70.5 kN dynamic load rating (C) and 36.5 kN static (C0), 2.85 kN fatigue load limit Cu, 6408 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 1230 g (1.2 kg), 6408 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 40×110×27 mm envelope of 6408 gives a D/d ratio of 2.75 and 35.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 70.5/36.5 kN load ratings, 2.85 kN fatigue load limit Cu NTN lists the grease limiting speed at 7000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1230 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6408 on the 40×110×27 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6408 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Order the C3 internal-clearance version (6408 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6408-NTN bearing?",
        "a": "A 6408-NTN deep-groove ball bearing has a 40 mm bore, 110 mm outer diameter and 27 mm width (1.575 × 4.331 × 1.063 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How should 6408-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 40 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6408-NTN need?",
        "a": "The open 6408-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "What is the NTN order number for an open 6408?",
        "a": "NTN lists the open 6408 under the bare designation 6408; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 40 mm bore envelope."
      },
      {
        "q": "Is 6408 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6408-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 40×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6408-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 40×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6408",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 40×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6408",
      "6408-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6408-ZZ",
    "brand": "NTN",
    "manufacturer_designation": "6408ZZ",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 40,
    "D_mm": 110,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 70.5,
    "static_load_kN": 36.5,
    "fatigue_load_limit_kN": 2.85,
    "limiting_speed_rpm": 7000,
    "max_rpm": 7000,
    "weight_g": 1230,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6408-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the heavy 64xx section (diameter series 4 of ISO 15), multiplying bore code 08 by five gives the 40 mm bore; the 110 mm outside diameter and 27 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 40 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6408ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Sizes around 40 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6408-ZZ.",
      "The 64xx heavy section at 40 mm bore exists for high radial load at moderate rpm; its 110 mm OD and 27 mm width demand a larger housing, and grease life at motor speeds is short — treat it as a low-speed, high-load choice.",
      "Do not wash 6408-ZZ in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6408-ZZ units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 110 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6408-ZZ.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues the shielded version as 6408ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 40 mm bore puts 6408 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7000 r/min the grease limiting speed for 6408 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 70.5 kN dynamic load rating (C) and 36.5 kN static (C0), 2.85 kN fatigue load limit Cu, 6408 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 1230 g (1.2 kg), 6408 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 40×110×27 mm envelope of 6408 gives a D/d ratio of 2.75 and 35.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 70.5/36.5 kN load ratings, 2.85 kN fatigue load limit Cu NTN lists the grease limiting speed at 7000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1230 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6408ZZ on the 40×110×27 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6408 in a rated drive.",
      "Standard catalogue stock of 6408 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6408 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6408-ZZ bearing?",
        "a": "A 6408-ZZ deep-groove ball bearing has a 40 mm bore, 110 mm outer diameter and 27 mm width (1.575 × 4.331 × 1.063 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 6408 bore code work?",
        "a": "The last two digits of 6408 are bore code 08, giving 08 × 5 = 40 mm bore. The 110 mm outside diameter and 27 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the ZZ suffix on 6408-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "What is the NTN suffix for a sealed 6408?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6408ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 40×110×27 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6408 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6408ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6408-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 40×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6408-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 40×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6408",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 40×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6408-zz",
      "6408zz",
      "6408-ZZ",
      "6408ZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61809-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6809JR",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 58,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.95,
    "static_load_kN": 4.95,
    "fatigue_load_limit_kN": 0.33,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "weight_g": 40,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61809 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 09 by five gives the 45 mm bore; the 58 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 45 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "At a 45 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61809-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "Only 6.5 mm of radial section separates bore and OD on the 618xx series at 45 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6209.",
      "The open 61809-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 45×58×7 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 61800-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61809 units.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "A 45 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "The open 61809 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 45 mm bore puts 61809 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 11000 r/min the grease limiting speed for 61809 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61809 at 5.95 kN dynamic (C) and 4.95 kN static (C0), 0.33 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 40 g, 61809 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 45×58×7 mm envelope of 61809 gives a D/d ratio of 1.29 and only 6.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 5.95/4.95 kN load ratings, 0.33 kN fatigue load limit Cu NTN lists the grease limiting speed at 11000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 40 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6809JR on the 45×58×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61809 in a rated drive.",
      "Standard catalogue stock of 61809 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61809 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61809-NTN bearing?",
        "a": "A 61809-NTN deep-groove ball bearing has a 45 mm bore, 58 mm outer diameter and 7 mm width (1.772 × 2.283 × 0.276 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What internal clearance does 61809-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61809-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61809 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61809-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 45 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN order number for an open 61809?",
        "a": "NTN lists the open 61809 under the bare designation 6809JR; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 45 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6809JR?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61809-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6809jr",
      "61809",
      "6809JR",
      "61809-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61809-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6809JRLLU",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 58,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.95,
    "static_load_kN": 4.95,
    "fatigue_load_limit_kN": 0.33,
    "limiting_speed_rpm": 5900,
    "max_rpm": 5900,
    "weight_g": 40,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61809-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 09 by five gives the 45 mm bore; the 58 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 45 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6809JRLLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "A 45 mm shaft for 61809 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 618xx thin section at 45 mm bore has only a 6.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6209.",
      "Contact seals add drag and heat: 61809-2RS-NTN runs slower and cooler-limited than the open 61809; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 61809-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Shaft and housing fillets must clear the bearing chamfer so the 7 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 58 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61809-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6809JRLLU (suffix RLLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 45 mm bore puts 61809 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5900 r/min the grease limiting speed for 61809 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 61809 at 5.95 kN dynamic (C) and 4.95 kN static (C0), 0.33 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 40 g, 61809 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 45×58×7 mm envelope of 61809 gives a D/d ratio of 1.29 and only 6.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 5.95/4.95 kN load ratings, 0.33 kN fatigue load limit Cu NTN lists the grease limiting speed at 5900 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 40 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6809JRLLU on the 45×58×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61809 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61809 is listed.",
      "Standard catalogue stock of 61809 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61809-2RS-NTN bearing?",
        "a": "A 61809-2RS-NTN deep-groove ball bearing has a 45 mm bore, 58 mm outer diameter and 7 mm width (1.772 × 2.283 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What internal clearance does 61809-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61809-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61809 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61809-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 45 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 61809?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6809JRLLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×58×7 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61809 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6809JRLLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61809-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61809-llu",
      "6809jrllu",
      "6809llu",
      "61809-2RS",
      "61809-2rs",
      "6809JRLLU",
      "61809-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61809-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6809JRLLB",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 58,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.95,
    "static_load_kN": 4.95,
    "fatigue_load_limit_kN": 0.33,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "weight_g": 40,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61809-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 09 by five gives the 45 mm bore; the 58 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 45 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6809JRLLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At a 45 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61809-RSR-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 618xx thin section at 45 mm bore has only a 6.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6209.",
      "RSR low-friction seals on 61809-RSR-NTN run faster than contact-seal 61809-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61809-2RS instead.",
      "The non-contact lip of 61809-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 45 mm bore position before relying on it as sealed-for-life.",
      "A 45 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Do not quieten a noisy bearing by preloading it: the 61800-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues this low-friction non-contact seal as 6809JRLLB (suffix RLLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 45 mm bore puts 61809 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 11000 r/min the grease limiting speed for 61809 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61809 at 5.95 kN dynamic (C) and 4.95 kN static (C0), 0.33 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 40 g, 61809 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 45×58×7 mm envelope of 61809 gives a D/d ratio of 1.29 and only 6.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 5.95/4.95 kN load ratings, 0.33 kN fatigue load limit Cu NTN lists the grease limiting speed at 11000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 40 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6809JRLLB on the 45×58×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61809 in a rated drive.",
      "Order the C3 internal-clearance version (61809 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61809 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61809-RSR-NTN bearing?",
        "a": "A 61809-RSR-NTN deep-groove ball bearing has a 45 mm bore, 58 mm outer diameter and 7 mm width (1.772 × 2.283 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What does the RSR suffix on 61809-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "How does the 61800 compare with other series at the same 45 mm bore?",
        "a": "618 is an extra-thin section: 58×7 mm, only 6.5 mm radial section at 45 mm bore, far smaller than a 6209, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "What is the NTN suffix for a sealed 61809?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6809JRLLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×58×7 mm ISO 15 envelope."
      },
      {
        "q": "Is 6809JRLLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61809-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61809-llb",
      "6809jrllb",
      "6809llb",
      "61809-RSR",
      "61809-rsr",
      "6809JRLLB",
      "61809-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61809-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6809JRZZ",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 58,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 5.95,
    "static_load_kN": 4.95,
    "fatigue_load_limit_kN": 0.33,
    "limiting_speed_rpm": 11000,
    "max_rpm": 11000,
    "weight_g": 40,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61809 carries bore code 09 = 45 mm. Outside diameter 58 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 45 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6809JRZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Sizes around 45 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 61809-ZZ-NTN.",
      "Only 6.5 mm of radial section separates bore and OD on the 618xx series at 45 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6209.",
      "ZZ shields are non-contact: 61809-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61809-2RS for that.",
      "Do not wash 61809-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61800-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61809-ZZ-NTN-C3. No clearance suffix means normal CN clearance.",
      "NTN catalogues the shielded version as 6809JRZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 45 mm bore puts 61809 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 11000 r/min the grease limiting speed for 61809 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61809 at 5.95 kN dynamic (C) and 4.95 kN static (C0), 0.33 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At only 40 g, 61809 is a lightweight bearing that can be handled by hand; still, press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.",
      "The 45×58×7 mm envelope of 61809 gives a D/d ratio of 1.29 and only 6.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 5.95/4.95 kN load ratings, 0.33 kN fatigue load limit Cu NTN lists the grease limiting speed at 11000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 40 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6809JRZZ on the 45×58×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61809 in a rated drive.",
      "Standard catalogue stock of 61809 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61809 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61809-ZZ-NTN bearing?",
        "a": "A 61809-ZZ-NTN deep-groove ball bearing has a 45 mm bore, 58 mm outer diameter and 7 mm width (1.772 × 2.283 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 61809-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 61800 compare with other series at the same 45 mm bore?",
        "a": "618 is an extra-thin section: 58×7 mm, only 6.5 mm radial section at 45 mm bore, far smaller than a 6209, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "What is the NTN suffix for a sealed 61809?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6809JRZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×58×7 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61809 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6809JRZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61809-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61809-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×58×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61809-zz",
      "6809jrzz",
      "6809zz",
      "61809-ZZ",
      "6809JRZZ",
      "61809-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61909-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6909",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 68,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 14.5,
    "static_load_kN": 10.4,
    "fatigue_load_limit_kN": 0.73,
    "limiting_speed_rpm": 9800,
    "max_rpm": 9800,
    "weight_g": 128,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61909 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 09 by five gives the 45 mm bore; the 68 mm outside diameter and 12 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 45 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "At a 45 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 61909-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 619xx thin section (11.5 mm section height at 45 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "The open 61909-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 45×68×12 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 61909-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 12 mm-wide ring of 61909-NTN drags the lip and overheats it.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "The open 61909 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 45 mm bore puts 61909 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 9800 r/min the grease limiting speed for 61909 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61909 at 14.5 kN dynamic (C) and 10.4 kN static (C0), 0.73 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 128 g, 61909 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 45×68×12 mm envelope of 61909 gives a D/d ratio of 1.51 and 11.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 14.5/10.4 kN load ratings, 0.73 kN fatigue load limit Cu NTN lists the grease limiting speed at 9800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 128 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6909 on the 45×68×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61909 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61909 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61909-NTN bearing?",
        "a": "A 61909-NTN deep-groove ball bearing has a 45 mm bore, 68 mm outer diameter and 12 mm width (1.772 × 2.677 × 0.472 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 61900 compare with other series at the same 45 mm bore?",
        "a": "619 is a thin section one step above 618: 68×12 mm with an 11.5 mm radial section at 45 mm bore; a 6209 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "Are 61909 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61909 uses the same ISO 15 envelope (45×68×12 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 61909?",
        "a": "NTN lists the open 61909 under the bare designation 6909; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 45 mm bore envelope."
      },
      {
        "q": "Is 6909 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61909-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61909-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6909",
      "61909",
      "61909-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61909-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6909LLU",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 68,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 14.5,
    "static_load_kN": 10.4,
    "fatigue_load_limit_kN": 0.73,
    "limiting_speed_rpm": 5600,
    "max_rpm": 5600,
    "weight_g": 128,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61909 carries bore code 09 = 45 mm. Outside diameter 68 mm and width 12 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 45 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6909LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "A 45 mm shaft for 61909 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 619xx thin section at 45 mm bore (11.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "Heat is the enemy of the sealed 61909-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 61909-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Never mix components between two 61909-2RS-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61900-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "NTN catalogues the contact-sealed version as 6909LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 45 mm bore puts 61909 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5600 r/min the grease limiting speed for 61909 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 61909 at 14.5 kN dynamic (C) and 10.4 kN static (C0), 0.73 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 128 g, 61909 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 45×68×12 mm envelope of 61909 gives a D/d ratio of 1.51 and 11.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 14.5/10.4 kN load ratings, 0.73 kN fatigue load limit Cu NTN lists the grease limiting speed at 5600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 128 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6909LLU on the 45×68×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61909 in a rated drive.",
      "Standard catalogue stock of 61909 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Order the C3 internal-clearance version (61909 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61909-2RS-NTN bearing?",
        "a": "A 61909-2RS-NTN deep-groove ball bearing has a 45 mm bore, 68 mm outer diameter and 12 mm width (1.772 × 2.677 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "Are 61909 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61909 uses the same ISO 15 envelope (45×68×12 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 61909-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61909-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61909 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 61909?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6909LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×68×12 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6909LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61909-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61909-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61909-llu",
      "6909llu",
      "61909-2RS",
      "61909-2rs",
      "6909LLU",
      "61909-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61909-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6909LLB",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 68,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 14.5,
    "static_load_kN": 10.4,
    "fatigue_load_limit_kN": 0.73,
    "limiting_speed_rpm": 9800,
    "max_rpm": 9800,
    "weight_g": 128,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61909-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 09 by five gives the 45 mm bore; the 68 mm outside diameter and 12 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 45 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6909LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Sizes around 45 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 61909-RSR-NTN.",
      "The 619xx thin section at 45 mm bore (11.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "The low-drag lip of 61909-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 61909-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 45 mm bore position before relying on it as sealed-for-life.",
      "A 45 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61900-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "NTN catalogues this low-friction non-contact seal as 6909LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 45 mm bore puts 61909 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 9800 r/min the grease limiting speed for 61909 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61909 at 14.5 kN dynamic (C) and 10.4 kN static (C0), 0.73 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 128 g, 61909 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 45×68×12 mm envelope of 61909 gives a D/d ratio of 1.51 and 11.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 14.5/10.4 kN load ratings, 0.73 kN fatigue load limit Cu NTN lists the grease limiting speed at 9800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 128 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6909LLB on the 45×68×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61909 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61909 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61909-RSR-NTN bearing?",
        "a": "A 61909-RSR-NTN deep-groove ball bearing has a 45 mm bore, 68 mm outer diameter and 12 mm width (1.772 × 2.677 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 61900 compare with other series at the same 45 mm bore?",
        "a": "619 is a thin section one step above 618: 68×12 mm with an 11.5 mm radial section at 45 mm bore; a 6209 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "Are 61909 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61909 uses the same ISO 15 envelope (45×68×12 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61909?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6909LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×68×12 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6909LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61909-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61909-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61909-llb",
      "6909llb",
      "61909-RSR",
      "61909-rsr",
      "6909LLB",
      "61909-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61909-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6909ZZ",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 68,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 14.5,
    "static_load_kN": 10.4,
    "fatigue_load_limit_kN": 0.73,
    "limiting_speed_rpm": 9800,
    "max_rpm": 9800,
    "weight_g": 128,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61909 carries bore code 09 = 45 mm. Outside diameter 68 mm and width 12 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 45 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6909ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "A 45 mm shaft for 61909 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 619xx thin section (11.5 mm section height at 45 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "ZZ shields are non-contact: 61909-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61909-2RS for that.",
      "Shielded 61909-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Never mix components between two 61909-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Vibration during standstill brinells the raceways of a 45 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues the shielded version as 6909ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 45 mm bore puts 61909 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 9800 r/min the grease limiting speed for 61909 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61909 at 14.5 kN dynamic (C) and 10.4 kN static (C0), 0.73 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 128 g, 61909 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 45×68×12 mm envelope of 61909 gives a D/d ratio of 1.51 and 11.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 14.5/10.4 kN load ratings, 0.73 kN fatigue load limit Cu NTN lists the grease limiting speed at 9800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 128 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6909ZZ on the 45×68×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61909 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Order the C3 internal-clearance version (61909 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61909-ZZ-NTN bearing?",
        "a": "A 61909-ZZ-NTN deep-groove ball bearing has a 45 mm bore, 68 mm outer diameter and 12 mm width (1.772 × 2.677 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 61909 bore code work?",
        "a": "The last two digits of 61909 are bore code 09, giving 09 × 5 = 45 mm bore. The 68 mm outside diameter and 12 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the ZZ suffix on 61909-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "What is the NTN suffix for a sealed 61909?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6909ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×68×12 mm ISO 15 envelope."
      },
      {
        "q": "Is 6909ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61909-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61909-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61909-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×68×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61909-zz",
      "6909zz",
      "61909-ZZ",
      "6909ZZ",
      "61909-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "16009",
    "brand": "NTN",
    "manufacturer_designation": "16009",
    "series": "16000-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 75,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 14.3,
    "static_load_kN": 10.5,
    "fatigue_load_limit_kN": 0.72,
    "limiting_speed_rpm": 9200,
    "max_rpm": 9200,
    "weight_g": 171,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 16000-series (the narrow extra-light section of ISO 15) the last two digits encode the bore: 16009 carries bore code 09 = 45 mm. Outside diameter 75 mm and width 10 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 45 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "At a 45 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 16009; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 160xx narrow section at 45 mm bore shares the 75 mm outside diameter of the 6009 but is only 10 mm wide; a 6009 in a 10 mm-wide seat is loose axially and the reverse swap will not fit — match width as well as bore and outside diameter.",
      "The open 16009 has no lubricant retention: grease escapes and contaminants migrate straight into the 45×75×10 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 16009 leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 75 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 16009.",
      "Vibration during standstill brinells the raceways of a 45 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "The open 16009 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 45 mm bore puts 16009 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 9200 r/min the grease limiting speed for 16009 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 16009 at 14.3 kN dynamic (C) and 10.5 kN static (C0), 0.72 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 171 g, 16009 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 45×75×10 mm envelope of 16009 gives a D/d ratio of 1.67 and 15.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 14.3/10.5 kN load ratings, 0.72 kN fatigue load limit Cu NTN lists the grease limiting speed at 9200 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 171 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 16009 on the 45×75×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 16009 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Standard catalogue stock of 16009 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 16009 bearing?",
        "a": "A 16009 deep-groove ball bearing has a 45 mm bore, 75 mm outer diameter and 10 mm width (1.772 × 2.953 × 0.394 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What does no suffix on 16009 mean?",
        "a": "A bare 16009 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "How does the 16000 compare with other series at the same 45 mm bore?",
        "a": "160 is the narrow extra-light section: 75×10 mm with a 15.0 mm radial section at 45 mm bore. It has the same bore and outside diameter as the 6009 but a narrower ring, so the two are not width-interchangeable; it appears in the manufacturer catalogues used on this site."
      },
      {
        "q": "What is the NTN order number for an open 16009?",
        "a": "NTN lists the open 16009 under the bare designation 16009; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 45 mm bore envelope."
      },
      {
        "q": "Is 16009 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "16009"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6009-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6009",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 75,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 23.2,
    "static_load_kN": 15.1,
    "fatigue_load_limit_kN": 1.16,
    "limiting_speed_rpm": 9200,
    "max_rpm": 9200,
    "weight_g": 237,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6009 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 09 by five gives the 45 mm bore; the 75 mm outside diameter and 16 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 45 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers",
      "electric motors"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "At a 45 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6009-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 60xx extra-light section at 45 mm bore uses a smaller 75 mm OD than a 6209; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "The open 6009-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 45×75×16 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 6000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6009 units.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 75 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6009-NTN.",
      "Vibration during standstill brinells the raceways of a 45 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "The open 6009 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 45 mm bore puts 6009 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 9200 r/min the grease limiting speed for 6009 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 23.2 kN dynamic load rating (C) and 15.1 kN static (C0), 1.16 kN fatigue load limit Cu, 6009 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 237 g, 6009 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 45×75×16 mm envelope of 6009 gives a D/d ratio of 1.67 and 15.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 23.2/15.1 kN load ratings, 1.16 kN fatigue load limit Cu NTN lists the grease limiting speed at 9200 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 237 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6009 on the 45×75×16 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6009 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6009 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6009-NTN bearing?",
        "a": "A 6009-NTN deep-groove ball bearing has a 45 mm bore, 75 mm outer diameter and 16 mm width (1.772 × 2.953 × 0.63 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6009 bore code work?",
        "a": "The last two digits of 6009 are bore code 09, giving 09 × 5 = 45 mm bore. The 75 mm outside diameter and 16 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does no suffix on 6009 mean?",
        "a": "A bare 6009 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "What is the NTN order number for an open 6009?",
        "a": "NTN lists the open 6009 under the bare designation 6009; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 45 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6009?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6009-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6009-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6009-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6009",
      "6009-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6009-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6009LLU",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 75,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 23.2,
    "static_load_kN": 15.1,
    "fatigue_load_limit_kN": 1.16,
    "limiting_speed_rpm": 5400,
    "max_rpm": 5400,
    "weight_g": 237,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6009 carries bore code 09 = 45 mm. Outside diameter 75 mm and width 16 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 45 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6009LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers",
      "electric motors"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "A 45 mm shaft for 6009 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "Choosing the 60xx extra-light section saves radial space at 45 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6209 before committing to the smaller envelope.",
      "Contact seals add drag and heat: 6009-2RS-NTN runs slower and cooler-limited than the open 6009; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 6009-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "The housing bore for the 75 mm OD should be round within IT7; an oval bore pinches the outer ring of 6009-2RS-NTN and shows up later as two-point loaded raceway wear.",
      "Shaft and housing fillets must clear the bearing chamfer so the 16 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues the contact-sealed version as 6009LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 45 mm bore puts 6009 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5400 r/min the grease limiting speed for 6009 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "At 23.2 kN dynamic load rating (C) and 15.1 kN static (C0), 1.16 kN fatigue load limit Cu, 6009 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 237 g, 6009 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 45×75×16 mm envelope of 6009 gives a D/d ratio of 1.67 and 15.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 23.2/15.1 kN load ratings, 1.16 kN fatigue load limit Cu NTN lists the grease limiting speed at 5400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 237 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6009LLU on the 45×75×16 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6009 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Order the C3 internal-clearance version (6009 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6009-2RS-NTN bearing?",
        "a": "A 6009-2RS-NTN deep-groove ball bearing has a 45 mm bore, 75 mm outer diameter and 16 mm width (1.772 × 2.953 × 0.63 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What lubrication does 6009-2RS-NTN need?",
        "a": "6009-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6009 with a housing grease fitting instead."
      },
      {
        "q": "How does the 6009 bore code work?",
        "a": "The last two digits of 6009 are bore code 09, giving 09 × 5 = 45 mm bore. The 75 mm outside diameter and 16 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6009?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6009LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×75×16 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6009 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6009LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6009-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6009-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6009-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6009-llu",
      "6009llu",
      "6009-2RS",
      "6009-2rs",
      "6009LLU",
      "6009-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6009-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6009LLB",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 75,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 23.2,
    "static_load_kN": 15.1,
    "fatigue_load_limit_kN": 1.16,
    "limiting_speed_rpm": 6500,
    "max_rpm": 6500,
    "weight_g": 237,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6009-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 09 by five gives the 45 mm bore; the 75 mm outside diameter and 16 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 45 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6009LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At a 45 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6009-RSR-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 60xx extra-light section at 45 mm bore uses a smaller 75 mm OD than a 6209; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "RSR low-friction seals on 6009-RSR-NTN run faster than contact-seal 6009-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6009-2RS instead.",
      "The low-drag lip of 6009-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The housing bore for the 75 mm OD should be round within IT7; an oval bore pinches the outer ring of 6009-RSR-NTN and shows up later as two-point loaded raceway wear.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 75 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6009-RSR-NTN.",
      "NTN catalogues this low-friction non-contact seal as 6009LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 45 mm bore puts 6009 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6500 r/min the grease limiting speed for 6009 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 23.2 kN dynamic load rating (C) and 15.1 kN static (C0), 1.16 kN fatigue load limit Cu, 6009 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 237 g, 6009 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 45×75×16 mm envelope of 6009 gives a D/d ratio of 1.67 and 15.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 23.2/15.1 kN load ratings, 1.16 kN fatigue load limit Cu NTN lists the grease limiting speed at 6500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 237 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6009LLB on the 45×75×16 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6009 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Order the C3 internal-clearance version (6009 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6009-RSR-NTN bearing?",
        "a": "A 6009-RSR-NTN deep-groove ball bearing has a 45 mm bore, 75 mm outer diameter and 16 mm width (1.772 × 2.953 × 0.63 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How should 6009-RSR-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 45 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6009-RSR-NTN need?",
        "a": "6009-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6009 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 6009?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6009LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×75×16 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6009 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6009LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6009-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6009-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6009-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6009-llb",
      "6009llb",
      "6009-RSR",
      "6009-rsr",
      "6009LLB",
      "6009-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6009-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6009ZZ",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 75,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 23.2,
    "static_load_kN": 15.1,
    "fatigue_load_limit_kN": 1.16,
    "limiting_speed_rpm": 6500,
    "max_rpm": 6500,
    "weight_g": 237,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6009-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 09 by five gives the 45 mm bore; the 75 mm outside diameter and 16 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 45 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6009ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "agricultural equipment",
      "fans and blowers",
      "electric motors",
      "centrifugal pumps"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "A 45 mm shaft for 6009 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 60xx extra-light section at 45 mm bore uses a smaller 75 mm OD than a 6209; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "ZZ shields are non-contact: 6009-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6009-2RS for that.",
      "Do not wash 6009-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6000-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "A 45 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues the shielded version as 6009ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 45 mm bore puts 6009 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6500 r/min the grease limiting speed for 6009 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 23.2 kN dynamic load rating (C) and 15.1 kN static (C0), 1.16 kN fatigue load limit Cu, 6009 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 237 g, 6009 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 45×75×16 mm envelope of 6009 gives a D/d ratio of 1.67 and 15.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 23.2/15.1 kN load ratings, 1.16 kN fatigue load limit Cu NTN lists the grease limiting speed at 6500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 237 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6009ZZ on the 45×75×16 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6009 in a rated drive.",
      "Standard catalogue stock of 6009 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Order the C3 internal-clearance version (6009 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6009-ZZ-NTN bearing?",
        "a": "A 6009-ZZ-NTN deep-groove ball bearing has a 45 mm bore, 75 mm outer diameter and 16 mm width (1.772 × 2.953 × 0.63 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 6009-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 6000 compare with other series at the same 45 mm bore?",
        "a": "The second digit is the diameter series: 60 is the smallest standard section (75×16 mm, 15.0 mm radial section) at 45 mm bore — below 62/63/64 in load capacity, for light loads in compact spaces."
      },
      {
        "q": "What is the NTN suffix for a sealed 6009?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6009ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×75×16 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6009ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6009-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6009-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6009-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6009-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×75×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6009-zz",
      "6009zz",
      "6009-ZZ",
      "6009ZZ",
      "6009-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6209-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6209",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 85,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 36,
    "static_load_kN": 20.4,
    "fatigue_load_limit_kN": 1.6,
    "limiting_speed_rpm": 7800,
    "max_rpm": 7800,
    "weight_g": 398,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6209 carries bore code 09 = 45 mm. Outside diameter 85 mm and width 19 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 45 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "At a 45 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6209-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 62xx light series is the default general-purpose section at 45 mm bore; before upgrading to a 6309 for extra capacity, confirm the housing accepts a 85 mm OD and 19 mm width — it is not a drop-in swap.",
      "Storage matters for open bearings: 6209-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 6200-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6209 units.",
      "A 45 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "The open 6209 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 45 mm bore puts 6209 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7800 r/min the grease limiting speed for 6209 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6209 at 36 kN dynamic (C) and 20.4 kN static (C0), 1.6 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 398 g, 6209 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 45×85×19 mm envelope of 6209 gives a D/d ratio of 1.89 and 20.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 36/20.4 kN load ratings, 1.6 kN fatigue load limit Cu NTN lists the grease limiting speed at 7800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 398 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6209 on the 45×85×19 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6209 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Order the C3 internal-clearance version (6209 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6209-NTN bearing?",
        "a": "A 6209-NTN deep-groove ball bearing has a 45 mm bore, 85 mm outer diameter and 19 mm width (1.772 × 3.346 × 0.748 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What does no suffix on 6209 mean?",
        "a": "A bare 6209 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "How does the 6200 compare with other series at the same 45 mm bore?",
        "a": "The '2' is the light diameter series: 85×19 mm with a 20.0 mm radial section at 45 mm bore. A 6309 on the same bore is larger and higher-rated; a 6009 is smaller and lower-rated."
      },
      {
        "q": "What is the NTN order number for an open 6209?",
        "a": "NTN lists the open 6209 under the bare designation 6209; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 45 mm bore envelope."
      },
      {
        "q": "Is 6209 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6209-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6209-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6209-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "209",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "209-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6209",
      "6209-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6209-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6209LLU",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 85,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 36,
    "static_load_kN": 20.4,
    "fatigue_load_limit_kN": 1.6,
    "limiting_speed_rpm": 5200,
    "max_rpm": 5200,
    "weight_g": 398,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6209-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 09 by five gives the 45 mm bore; the 85 mm outside diameter and 19 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 45 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6209LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "electric motors",
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "At a 45 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6209-2RS-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "At 45 mm bore the 62xx light series is the workhorse section; its 85×19 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "Contact seals add drag and heat: 6209-2RS-NTN runs slower and cooler-limited than the open 6209; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 6209-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6209-2RS-NTN-C3. No clearance suffix means normal CN clearance.",
      "Never mix components between two 6209-2RS-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the contact-sealed version as 6209LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 45 mm bore puts 6209 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5200 r/min the grease limiting speed for 6209 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 6209 at 36 kN dynamic (C) and 20.4 kN static (C0), 1.6 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 398 g, 6209 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 45×85×19 mm envelope of 6209 gives a D/d ratio of 1.89 and 20.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 36/20.4 kN load ratings, 1.6 kN fatigue load limit Cu NTN lists the grease limiting speed at 5200 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 398 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6209LLU on the 45×85×19 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6209 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Order the C3 internal-clearance version (6209 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6209-2RS-NTN bearing?",
        "a": "A 6209-2RS-NTN deep-groove ball bearing has a 45 mm bore, 85 mm outer diameter and 19 mm width (1.772 × 3.346 × 0.748 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How should 6209-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 45 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6209-2RS-NTN need?",
        "a": "6209-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6209 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 6209?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6209LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×85×19 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6209 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6209LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6209-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6209-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6209-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "209",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "209-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6209-llu",
      "6209llu",
      "6209-2RS",
      "6209-2rs",
      "6209LLU",
      "6209-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6209-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6209LLB",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 85,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 36,
    "static_load_kN": 20.4,
    "fatigue_load_limit_kN": 1.6,
    "limiting_speed_rpm": 6200,
    "max_rpm": 6200,
    "weight_g": 398,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6209-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 09 by five gives the 45 mm bore; the 85 mm outside diameter and 19 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 45 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6209LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "electric motors",
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "At a 45 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6209-RSR-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 62xx light series is the default general-purpose section at 45 mm bore; before upgrading to a 6309 for extra capacity, confirm the housing accepts a 85 mm OD and 19 mm width — it is not a drop-in swap.",
      "RSR low-friction seals on 6209-RSR-NTN run faster than contact-seal 6209-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6209-2RS instead.",
      "The low-drag lip of 6209-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "Measure the shaft, do not trust the drawing: a 45 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6209-RSR-NTN.",
      "Do not quieten a noisy bearing by preloading it: the 6200-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues this low-friction non-contact seal as 6209LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 45 mm bore puts 6209 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6200 r/min the grease limiting speed for 6209 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6209 at 36 kN dynamic (C) and 20.4 kN static (C0), 1.6 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 398 g, 6209 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 45×85×19 mm envelope of 6209 gives a D/d ratio of 1.89 and 20.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 36/20.4 kN load ratings, 1.6 kN fatigue load limit Cu NTN lists the grease limiting speed at 6200 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 398 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6209LLB on the 45×85×19 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6209 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Order the C3 internal-clearance version (6209 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6209-RSR-NTN bearing?",
        "a": "A 6209-RSR-NTN deep-groove ball bearing has a 45 mm bore, 85 mm outer diameter and 19 mm width (1.772 × 3.346 × 0.748 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6200 compare with other series at the same 45 mm bore?",
        "a": "The '2' is the light diameter series: 85×19 mm with a 20.0 mm radial section at 45 mm bore. A 6309 on the same bore is larger and higher-rated; a 6009 is smaller and lower-rated."
      },
      {
        "q": "Are 6209 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6209 uses the same ISO 15 envelope (45×85×19 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6209?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6209LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×85×19 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6209LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6209-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6209-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6209-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "209",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "209-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6209-llb",
      "6209llb",
      "6209-RSR",
      "6209-rsr",
      "6209LLB",
      "6209-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6209-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6209ZZ",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 85,
    "B_mm": 19,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 36,
    "static_load_kN": 20.4,
    "fatigue_load_limit_kN": 1.6,
    "limiting_speed_rpm": 6200,
    "max_rpm": 6200,
    "weight_g": 398,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6209 carries bore code 09 = 45 mm. Outside diameter 85 mm and width 19 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 45 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6209ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "centrifugal pumps",
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "At a 45 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6209-ZZ-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "At 45 mm bore the 62xx light series is the workhorse section; its 85×19 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "Do not wash 6209-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6209-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Vibration during standstill brinells the raceways of a 45 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Do not quieten a noisy bearing by preloading it: the 6200-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues the shielded version as 6209ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 45 mm bore puts 6209 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6200 r/min the grease limiting speed for 6209 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6209 at 36 kN dynamic (C) and 20.4 kN static (C0), 1.6 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 398 g, 6209 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 45×85×19 mm envelope of 6209 gives a D/d ratio of 1.89 and 20.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 36/20.4 kN load ratings, 1.6 kN fatigue load limit Cu NTN lists the grease limiting speed at 6200 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 398 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6209ZZ on the 45×85×19 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6209 in a rated drive.",
      "Standard catalogue stock of 6209 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6209-ZZ-NTN bearing?",
        "a": "A 6209-ZZ-NTN deep-groove ball bearing has a 45 mm bore, 85 mm outer diameter and 19 mm width (1.772 × 3.346 × 0.748 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 6200 compare with other series at the same 45 mm bore?",
        "a": "The '2' is the light diameter series: 85×19 mm with a 20.0 mm radial section at 45 mm bore. A 6309 on the same bore is larger and higher-rated; a 6009 is smaller and lower-rated."
      },
      {
        "q": "Are 6209 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6209 uses the same ISO 15 envelope (45×85×19 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6209?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6209ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×85×19 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6209ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6209-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6209-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6209-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6209-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "209",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "209-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×85×19 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6209-zz",
      "6209zz",
      "6209-ZZ",
      "6209ZZ",
      "6209-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6309-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6309",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 58.5,
    "static_load_kN": 32,
    "fatigue_load_limit_kN": 2.5,
    "limiting_speed_rpm": 7000,
    "max_rpm": 7000,
    "weight_g": 814,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6309 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 09 by five gives the 45 mm bore; the 100 mm outside diameter and 25 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 45 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Sizes around 45 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6309-NTN.",
      "The 63xx medium series gains rating at 45 mm bore through a 100 mm OD and 25 mm width; the heavier rolling elements also trade away some speed versus a 6209.",
      "The open 6309-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 45×100×25 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6309-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Do not quieten a noisy bearing by preloading it: the 6300-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 25 mm-wide ring of 6309-NTN drags the lip and overheats it.",
      "The open 6309 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 45 mm bore puts 6309 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7000 r/min the grease limiting speed for 6309 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6309 at 58.5 kN dynamic (C) and 32 kN static (C0), 2.5 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 814 g, 6309 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 45×100×25 mm envelope of 6309 gives a D/d ratio of 2.22 and 27.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 58.5/32 kN load ratings, 2.5 kN fatigue load limit Cu NTN lists the grease limiting speed at 7000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 814 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6309 on the 45×100×25 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6309 in a rated drive.",
      "Standard catalogue stock of 6309 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6309 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6309-NTN bearing?",
        "a": "A 6309-NTN deep-groove ball bearing has a 45 mm bore, 100 mm outer diameter and 25 mm width (1.772 × 3.937 × 0.984 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6309 bore code work?",
        "a": "The last two digits of 6309 are bore code 09, giving 09 × 5 = 45 mm bore. The 100 mm outside diameter and 25 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does no suffix on 6309 mean?",
        "a": "A bare 6309 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "What is the NTN order number for an open 6309?",
        "a": "NTN lists the open 6309 under the bare designation 6309; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 45 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6309?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6309-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "309",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "309-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6309",
      "6309-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6309-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6309LLU",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 58.5,
    "static_load_kN": 32,
    "fatigue_load_limit_kN": 2.5,
    "limiting_speed_rpm": 4700,
    "max_rpm": 4700,
    "weight_g": 814,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6309 carries bore code 09 = 45 mm. Outside diameter 100 mm and width 25 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 45 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6309LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "A 45 mm shaft for 6309 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 63xx medium section at 45 mm bore gains dynamic rating through larger rolling elements on a 100 mm OD; the penalty is mass and a lower limiting speed than the 6209 — do not specify it for speed-critical shafts.",
      "Contact seals add drag and heat: 6309-2RS-NTN runs slower and cooler-limited than the open 6309; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 6309-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "The housing bore for the 100 mm OD should be round within IT7; an oval bore pinches the outer ring of 6309-2RS-NTN and shows up later as two-point loaded raceway wear.",
      "Measure the shaft, do not trust the drawing: a 45 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6309-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6309LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 45 mm bore puts 6309 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN lists the grease limiting speed at 4700 r/min for 6309; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "NTN rates 6309 at 58.5 kN dynamic (C) and 32 kN static (C0), 2.5 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 814 g, 6309 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 45×100×25 mm envelope of 6309 gives a D/d ratio of 2.22 and 27.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 58.5/32 kN load ratings, 2.5 kN fatigue load limit Cu NTN lists the grease limiting speed at 4700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 814 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6309LLU on the 45×100×25 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6309 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6309-2RS-NTN bearing?",
        "a": "A 6309-2RS-NTN deep-groove ball bearing has a 45 mm bore, 100 mm outer diameter and 25 mm width (1.772 × 3.937 × 0.984 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What internal clearance does 6309-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6309-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6309 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6309-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 45 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 6309?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6309LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×100×25 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6309 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6309LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6309-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "309",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "309-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6309-llu",
      "6309llu",
      "6309-2RS",
      "6309-2rs",
      "6309LLU",
      "6309-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6309-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6309LLB",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 58.5,
    "static_load_kN": 32,
    "fatigue_load_limit_kN": 2.5,
    "limiting_speed_rpm": 5600,
    "max_rpm": 5600,
    "weight_g": 814,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6309 carries bore code 09 = 45 mm. Outside diameter 100 mm and width 25 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 45 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6309LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "small gearboxes",
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "At a 45 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6309-RSR-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.",
      "The 63xx medium series gains rating at 45 mm bore through a 100 mm OD and 25 mm width; the heavier rolling elements also trade away some speed versus a 6209.",
      "RSR low-friction seals on 6309-RSR-NTN run faster than contact-seal 6309-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6309-2RS instead.",
      "The low-drag lip of 6309-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 100 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6309-RSR-NTN.",
      "Measure the shaft, do not trust the drawing: a 45 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6309-RSR-NTN.",
      "NTN catalogues this low-friction non-contact seal as 6309LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 45 mm bore puts 6309 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5600 r/min the grease limiting speed for 6309 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6309 at 58.5 kN dynamic (C) and 32 kN static (C0), 2.5 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 814 g, 6309 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 45×100×25 mm envelope of 6309 gives a D/d ratio of 2.22 and 27.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 58.5/32 kN load ratings, 2.5 kN fatigue load limit Cu NTN lists the grease limiting speed at 5600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 814 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6309LLB on the 45×100×25 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6309 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6309 is listed.",
      "Order the C3 internal-clearance version (6309 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6309-RSR-NTN bearing?",
        "a": "A 6309-RSR-NTN deep-groove ball bearing has a 45 mm bore, 100 mm outer diameter and 25 mm width (1.772 × 3.937 × 0.984 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6309 bore code work?",
        "a": "The last two digits of 6309 are bore code 09, giving 09 × 5 = 45 mm bore. The 100 mm outside diameter and 25 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the RSR suffix on 6309-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "What is the NTN suffix for a sealed 6309?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6309LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×100×25 mm ISO 15 envelope."
      },
      {
        "q": "Is 6309LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6309-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "309",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "309-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6309-llb",
      "6309llb",
      "6309-RSR",
      "6309-rsr",
      "6309LLB",
      "6309-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6309-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6309ZZ",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 100,
    "B_mm": 25,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 58.5,
    "static_load_kN": 32,
    "fatigue_load_limit_kN": 2.5,
    "limiting_speed_rpm": 5600,
    "max_rpm": 5600,
    "weight_g": 814,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6309-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 09 by five gives the 45 mm bore; the 100 mm outside diameter and 25 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 45 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6309ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "conveyors and drives",
      "agricultural equipment",
      "fans and blowers",
      "electric motors"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "A 45 mm shaft for 6309 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 63xx medium series gains rating at 45 mm bore through a 100 mm OD and 25 mm width; the heavier rolling elements also trade away some speed versus a 6209.",
      "Do not wash 6309-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6309-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6309-ZZ-NTN-C3. No clearance suffix means normal CN clearance.",
      "Vibration during standstill brinells the raceways of a 45 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues the shielded version as 6309ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 45 mm bore puts 6309 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5600 r/min the grease limiting speed for 6309 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6309 at 58.5 kN dynamic (C) and 32 kN static (C0), 2.5 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 814 g, 6309 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 45×100×25 mm envelope of 6309 gives a D/d ratio of 2.22 and 27.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 58.5/32 kN load ratings, 2.5 kN fatigue load limit Cu NTN lists the grease limiting speed at 5600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 814 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6309ZZ on the 45×100×25 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6309 in a rated drive.",
      "Order the C3 internal-clearance version (6309 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6309-ZZ-NTN bearing?",
        "a": "A 6309-ZZ-NTN deep-groove ball bearing has a 45 mm bore, 100 mm outer diameter and 25 mm width (1.772 × 3.937 × 0.984 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 6309 bore code work?",
        "a": "The last two digits of 6309 are bore code 09, giving 09 × 5 = 45 mm bore. The 100 mm outside diameter and 25 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the ZZ suffix on 6309-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "What is the NTN suffix for a sealed 6309?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6309ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×100×25 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6309 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6309ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6309-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6309-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "309",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "309-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×100×25 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6309-zz",
      "6309zz",
      "6309-ZZ",
      "6309ZZ",
      "6309-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6409-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6409",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 120,
    "B_mm": 29,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 85.5,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 3.5,
    "limiting_speed_rpm": 6300,
    "max_rpm": 6300,
    "weight_g": 1530,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6400-series (diameter series 4 of ISO 15) the last two digits encode the bore: 6409 carries bore code 09 = 45 mm. Outside diameter 120 mm and width 29 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 45 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "fans and blowers",
      "electric motors",
      "centrifugal pumps",
      "small gearboxes"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Sizes around 45 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6409-NTN.",
      "The 64xx heavy section at 45 mm bore exists for high radial load at moderate rpm; its 120 mm OD and 29 mm width demand a larger housing, and grease life at motor speeds is short — treat it as a low-speed, high-load choice.",
      "Storage matters for open bearings: 6409-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 6400-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6409 units.",
      "A 45 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "The housing bore for the 120 mm OD should be round within IT7; an oval bore pinches the outer ring of 6409-NTN and shows up later as two-point loaded raceway wear.",
      "The open 6409 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 45 mm bore puts 6409 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6300 r/min the grease limiting speed for 6409 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 85.5 kN dynamic load rating (C) and 45 kN static (C0), 3.5 kN fatigue load limit Cu, 6409 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 1530 g (1.5 kg), 6409 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 45×120×29 mm envelope of 6409 gives a D/d ratio of 2.67 and 37.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 85.5/45 kN load ratings, 3.5 kN fatigue load limit Cu NTN lists the grease limiting speed at 6300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1530 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6409 on the 45×120×29 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6409 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6409-NTN bearing?",
        "a": "A 6409-NTN deep-groove ball bearing has a 45 mm bore, 120 mm outer diameter and 29 mm width (1.772 × 4.724 × 1.142 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What lubrication does 6409-NTN need?",
        "a": "The open 6409-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "How does the 6409 bore code work?",
        "a": "The last two digits of 6409 are bore code 09, giving 09 × 5 = 45 mm bore. The 120 mm outside diameter and 29 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN order number for an open 6409?",
        "a": "NTN lists the open 6409 under the bare designation 6409; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 45 mm bore envelope."
      },
      {
        "q": "Is 6409 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6409-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 45×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6409",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6409",
      "6409-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6409-ZZ",
    "brand": "NTN",
    "manufacturer_designation": "6409ZZ",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 45,
    "D_mm": 120,
    "B_mm": 29,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 85.5,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 3.5,
    "limiting_speed_rpm": 6300,
    "max_rpm": 6300,
    "weight_g": 1530,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6409-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the heavy 64xx section (diameter series 4 of ISO 15), multiplying bore code 09 by five gives the 45 mm bore; the 120 mm outside diameter and 29 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 45 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6409ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "fans and blowers",
      "electric motors",
      "centrifugal pumps",
      "small gearboxes"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "A 45 mm shaft for 6409 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.",
      "The 64xx heavy section at 45 mm bore exists for high radial load at moderate rpm; its 120 mm OD and 29 mm width demand a larger housing, and grease life at motor speeds is short — treat it as a low-speed, high-load choice.",
      "Do not wash 6409-ZZ in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6409-ZZ units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Do not quieten a noisy bearing by preloading it: the 6400-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "A 45 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues the shielded version as 6409ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 45 mm bore puts 6409 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6300 r/min the grease limiting speed for 6409 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 85.5 kN dynamic load rating (C) and 45 kN static (C0), 3.5 kN fatigue load limit Cu, 6409 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 1530 g (1.5 kg), 6409 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 45×120×29 mm envelope of 6409 gives a D/d ratio of 2.67 and 37.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 85.5/45 kN load ratings, 3.5 kN fatigue load limit Cu NTN lists the grease limiting speed at 6300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1530 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6409ZZ on the 45×120×29 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6409 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6409 is listed.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6409-ZZ bearing?",
        "a": "A 6409-ZZ deep-groove ball bearing has a 45 mm bore, 120 mm outer diameter and 29 mm width (1.772 × 4.724 × 1.142 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "Are 6409 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6409 uses the same ISO 15 envelope (45×120×29 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 6409-ZZ have?",
        "a": "Unless a clearance suffix says otherwise, 6409-ZZ is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6409 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 6409?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6409ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 45×120×29 mm ISO 15 envelope."
      },
      {
        "q": "Is 6409ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6409-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 45×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6409",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 45×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6409-zz",
      "6409zz",
      "6409-ZZ",
      "6409ZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61810-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6810JR",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 65,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 7.3,
    "static_load_kN": 6.1,
    "fatigue_load_limit_kN": 0.41,
    "limiting_speed_rpm": 9600,
    "max_rpm": 9600,
    "weight_g": 52,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61810 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 10 by five gives the 50 mm bore; the 65 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 50 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "At 50 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61810 against the shaft shoulder while it cools so the ring cannot creep back.",
      "Only 7.5 mm of radial section separates bore and OD on the 618xx series at 50 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6210.",
      "Storage matters for open bearings: 61810-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 61800-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61810 units.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Shaft and housing fillets must clear the bearing chamfer so the 7 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "The open 61810 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 50 mm bore puts 61810 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 9600 r/min the grease limiting speed for 61810 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61810 at 7.3 kN dynamic (C) and 6.1 kN static (C0), 0.41 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 52 g, 61810 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 50×65×7 mm envelope of 61810 gives a D/d ratio of 1.30 and only 7.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 7.3/6.1 kN load ratings, 0.41 kN fatigue load limit Cu NTN lists the grease limiting speed at 9600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 52 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6810JR on the 50×65×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61810 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61810-NTN bearing?",
        "a": "A 61810-NTN deep-groove ball bearing has a 50 mm bore, 65 mm outer diameter and 7 mm width (1.969 × 2.559 × 0.276 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What lubrication does 61810-NTN need?",
        "a": "The open 61810-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "How does the 61810 bore code work?",
        "a": "The last two digits of 61810 are bore code 10, giving 10 × 5 = 50 mm bore. The 65 mm outside diameter and 7 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN order number for an open 61810?",
        "a": "NTN lists the open 61810 under the bare designation 6810JR; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 50 mm bore envelope."
      },
      {
        "q": "Is 6810JR a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61810-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61810-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6810jr",
      "61810",
      "6810JR",
      "61810-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61810-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6810JRLLU",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 65,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 7.3,
    "static_load_kN": 6.1,
    "fatigue_load_limit_kN": 0.41,
    "limiting_speed_rpm": 5300,
    "max_rpm": 5300,
    "weight_g": 52,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61810 carries bore code 10 = 50 mm. Outside diameter 65 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 50 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6810JRLLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 50 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61810 with C3 for those conditions.",
      "Only 7.5 mm of radial section separates bore and OD on the 618xx series at 50 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6210.",
      "Heat is the enemy of the sealed 61810-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 61810-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61810-2RS-NTN-C3. No clearance suffix means normal CN clearance.",
      "Shaft and housing fillets must clear the bearing chamfer so the 7 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues the contact-sealed version as 6810JRLLU (suffix RLLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 50 mm bore puts 61810 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5300 r/min the grease limiting speed for 61810 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 61810 at 7.3 kN dynamic (C) and 6.1 kN static (C0), 0.41 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 52 g, 61810 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 50×65×7 mm envelope of 61810 gives a D/d ratio of 1.30 and only 7.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 7.3/6.1 kN load ratings, 0.41 kN fatigue load limit Cu NTN lists the grease limiting speed at 5300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 52 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6810JRLLU on the 50×65×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61810 in a rated drive.",
      "Standard catalogue stock of 61810 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61810-2RS-NTN bearing?",
        "a": "A 61810-2RS-NTN deep-groove ball bearing has a 50 mm bore, 65 mm outer diameter and 7 mm width (1.969 × 2.559 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "Are 61810 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61810 uses the same ISO 15 envelope (50×65×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 61810-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61810-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61810 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 61810?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6810JRLLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×65×7 mm ISO 15 envelope."
      },
      {
        "q": "Is 6810JRLLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61810-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61810-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61810-llu",
      "6810jrllu",
      "6810llu",
      "61810-2RS",
      "61810-2rs",
      "6810JRLLU",
      "61810-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61810-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6810JRLLB",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 65,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 7.3,
    "static_load_kN": 6.1,
    "fatigue_load_limit_kN": 0.41,
    "limiting_speed_rpm": 9600,
    "max_rpm": 9600,
    "weight_g": 52,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61810-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 10 by five gives the 50 mm bore; the 65 mm outside diameter and 7 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 50 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6810JRLLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 50 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61810 with C3 for those conditions.",
      "Only 7.5 mm of radial section separates bore and OD on the 618xx series at 50 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6210.",
      "The low-drag lip of 61810-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 61810-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 50 mm bore position before relying on it as sealed-for-life.",
      "Do not quieten a noisy bearing by preloading it: the 61800-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues this low-friction non-contact seal as 6810JRLLB (suffix RLLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 50 mm bore puts 61810 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 9600 r/min the grease limiting speed for 61810 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61810 at 7.3 kN dynamic (C) and 6.1 kN static (C0), 0.41 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 52 g, 61810 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 50×65×7 mm envelope of 61810 gives a D/d ratio of 1.30 and only 7.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 7.3/6.1 kN load ratings, 0.41 kN fatigue load limit Cu NTN lists the grease limiting speed at 9600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 52 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6810JRLLB on the 50×65×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61810 in a rated drive.",
      "Standard catalogue stock of 61810 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61810-RSR-NTN bearing?",
        "a": "A 61810-RSR-NTN deep-groove ball bearing has a 50 mm bore, 65 mm outer diameter and 7 mm width (1.969 × 2.559 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 61800 compare with other series at the same 50 mm bore?",
        "a": "618 is an extra-thin section: 65×7 mm, only 7.5 mm radial section at 50 mm bore, far smaller than a 6210, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "Are 61810 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61810 uses the same ISO 15 envelope (50×65×7 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61810?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6810JRLLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×65×7 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6810JRLLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61810-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61810-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61810-llb",
      "6810jrllb",
      "6810llb",
      "61810-RSR",
      "61810-rsr",
      "6810JRLLB",
      "61810-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61810-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6810JRZZ",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 65,
    "B_mm": 7,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 7.3,
    "static_load_kN": 6.1,
    "fatigue_load_limit_kN": 0.41,
    "limiting_speed_rpm": 9600,
    "max_rpm": 9600,
    "weight_g": 52,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61810 carries bore code 10 = 50 mm. Outside diameter 65 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 50 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6810JRZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At 50 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61810 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 618xx thin section at 50 mm bore has only a 7.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6210.",
      "ZZ shields are non-contact: 61810-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61810-2RS for that.",
      "Do not wash 61810-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "The housing bore for the 65 mm OD should be round within IT7; an oval bore pinches the outer ring of 61810-ZZ-NTN and shows up later as two-point loaded raceway wear.",
      "NTN catalogues the shielded version as 6810JRZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 50 mm bore puts 61810 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 9600 r/min the grease limiting speed for 61810 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61810 at 7.3 kN dynamic (C) and 6.1 kN static (C0), 0.41 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 52 g, 61810 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 50×65×7 mm envelope of 61810 gives a D/d ratio of 1.30 and only 7.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 7.3/6.1 kN load ratings, 0.41 kN fatigue load limit Cu NTN lists the grease limiting speed at 9600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 52 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6810JRZZ on the 50×65×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61810 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61810-ZZ-NTN bearing?",
        "a": "A 61810-ZZ-NTN deep-groove ball bearing has a 50 mm bore, 65 mm outer diameter and 7 mm width (1.969 × 2.559 × 0.276 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What internal clearance does 61810-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61810-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61810 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61810-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 50 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 61810?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6810JRZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×65×7 mm ISO 15 envelope."
      },
      {
        "q": "Is 6810JRZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61810-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61810-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W61810-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×65×7 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61810-zz",
      "6810jrzz",
      "6810zz",
      "61810-ZZ",
      "6810JRZZ",
      "61810-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61910-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6910",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 72,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 14.9,
    "static_load_kN": 11.2,
    "fatigue_load_limit_kN": 0.77,
    "limiting_speed_rpm": 8900,
    "max_rpm": 8900,
    "weight_g": 132,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61910 carries bore code 10 = 50 mm. Outside diameter 72 mm and width 12 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 50 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "At 50 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61910 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 619xx thin section (11.0 mm section height at 50 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "Storage matters for open bearings: 61910-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 61900-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61910 units.",
      "Vibration during standstill brinells the raceways of a 50 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "The open 61910 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 50 mm bore puts 61910 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8900 r/min the grease limiting speed for 61910 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61910 at 14.9 kN dynamic (C) and 11.2 kN static (C0), 0.77 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 132 g, 61910 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 50×72×12 mm envelope of 61910 gives a D/d ratio of 1.44 and 11.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 14.9/11.2 kN load ratings, 0.77 kN fatigue load limit Cu NTN lists the grease limiting speed at 8900 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 132 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6910 on the 50×72×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61910 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61910 is listed.",
      "Standard catalogue stock of 61910 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61910-NTN bearing?",
        "a": "A 61910-NTN deep-groove ball bearing has a 50 mm bore, 72 mm outer diameter and 12 mm width (1.969 × 2.835 × 0.472 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 61900 compare with other series at the same 50 mm bore?",
        "a": "619 is a thin section one step above 618: 72×12 mm with an 11.0 mm radial section at 50 mm bore; a 6210 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "Are 61910 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61910 uses the same ISO 15 envelope (50×72×12 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 61910?",
        "a": "NTN lists the open 61910 under the bare designation 6910; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 50 mm bore envelope."
      },
      {
        "q": "Is 6910 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61910-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6910",
      "61910",
      "61910-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61910-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6910LLU",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 72,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 14.9,
    "static_load_kN": 11.2,
    "fatigue_load_limit_kN": 0.77,
    "limiting_speed_rpm": 5100,
    "max_rpm": 5100,
    "weight_g": 132,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61910 carries bore code 10 = 50 mm. Outside diameter 72 mm and width 12 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 50 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6910LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 50 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61910 with C3 for those conditions.",
      "The 619xx thin section at 50 mm bore (11.0 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "Heat is the enemy of the sealed 61910-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 61910-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61910-2RS-NTN-C3. No clearance suffix means normal CN clearance.",
      "A 50 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues the contact-sealed version as 6910LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 50 mm bore puts 61910 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5100 r/min the grease limiting speed for 61910 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "NTN rates 61910 at 14.9 kN dynamic (C) and 11.2 kN static (C0), 0.77 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 132 g, 61910 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 50×72×12 mm envelope of 61910 gives a D/d ratio of 1.44 and 11.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 14.9/11.2 kN load ratings, 0.77 kN fatigue load limit Cu NTN lists the grease limiting speed at 5100 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 132 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6910LLU on the 50×72×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61910 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Standard catalogue stock of 61910 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61910-2RS-NTN bearing?",
        "a": "A 61910-2RS-NTN deep-groove ball bearing has a 50 mm bore, 72 mm outer diameter and 12 mm width (1.969 × 2.835 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How should 61910-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 50 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 61910-2RS-NTN need?",
        "a": "61910-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61910 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 61910?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6910LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×72×12 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61910 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6910LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61910-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61910-llu",
      "6910llu",
      "61910-2RS",
      "61910-2rs",
      "6910LLU",
      "61910-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61910-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6910LLB",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 72,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 14.9,
    "static_load_kN": 11.2,
    "fatigue_load_limit_kN": 0.77,
    "limiting_speed_rpm": 6100,
    "max_rpm": 6100,
    "weight_g": 132,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61910-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 10 by five gives the 50 mm bore; the 72 mm outside diameter and 12 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 50 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6910LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Interference on a 50 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61910 with C3 clearance and re-check the residual value after mounting.",
      "The 619xx thin section at 50 mm bore (11.0 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "RSR low-friction seals on 61910-RSR-NTN run faster than contact-seal 61910-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61910-2RS instead.",
      "The non-contact lip of 61910-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 50 mm bore position before relying on it as sealed-for-life.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61910-RSR-NTN-C3. No clearance suffix means normal CN clearance.",
      "Measure the shaft, do not trust the drawing: a 50 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61910-RSR-NTN.",
      "NTN catalogues this low-friction non-contact seal as 6910LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 50 mm bore puts 61910 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6100 r/min the grease limiting speed for 61910 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61910 at 14.9 kN dynamic (C) and 11.2 kN static (C0), 0.77 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 132 g, 61910 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 50×72×12 mm envelope of 61910 gives a D/d ratio of 1.44 and 11.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 14.9/11.2 kN load ratings, 0.77 kN fatigue load limit Cu NTN lists the grease limiting speed at 6100 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 132 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6910LLB on the 50×72×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61910 in a rated drive.",
      "Standard catalogue stock of 61910 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Order the C3 internal-clearance version (61910 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61910-RSR-NTN bearing?",
        "a": "A 61910-RSR-NTN deep-groove ball bearing has a 50 mm bore, 72 mm outer diameter and 12 mm width (1.969 × 2.835 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 61900 compare with other series at the same 50 mm bore?",
        "a": "619 is a thin section one step above 618: 72×12 mm with an 11.0 mm radial section at 50 mm bore; a 6210 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "Are 61910 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61910 uses the same ISO 15 envelope (50×72×12 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61910?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6910LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×72×12 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61910 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6910LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61910-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61910-llb",
      "6910llb",
      "61910-RSR",
      "61910-rsr",
      "6910LLB",
      "61910-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61910-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6910ZZ",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 72,
    "B_mm": 12,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 14.9,
    "static_load_kN": 11.2,
    "fatigue_load_limit_kN": 0.77,
    "limiting_speed_rpm": 6100,
    "max_rpm": 6100,
    "weight_g": 132,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61910-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 10 by five gives the 50 mm bore; the 72 mm outside diameter and 12 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 50 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6910ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Interference on a 50 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61910 with C3 clearance and re-check the residual value after mounting.",
      "The 619xx thin section (11.0 mm section height at 50 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "ZZ shields are non-contact: 61910-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61910-2RS for that.",
      "Do not wash 61910-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Vibration during standstill brinells the raceways of a 50 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Never mix components between two 61910-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the shielded version as 6910ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 50 mm bore puts 61910 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6100 r/min the grease limiting speed for 61910 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61910 at 14.9 kN dynamic (C) and 11.2 kN static (C0), 0.77 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 132 g, 61910 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 50×72×12 mm envelope of 61910 gives a D/d ratio of 1.44 and 11.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 14.9/11.2 kN load ratings, 0.77 kN fatigue load limit Cu NTN lists the grease limiting speed at 6100 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 132 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6910ZZ on the 50×72×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61910 in a rated drive.",
      "Order the C3 internal-clearance version (61910 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Standard catalogue stock of 61910 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61910-ZZ-NTN bearing?",
        "a": "A 61910-ZZ-NTN deep-groove ball bearing has a 50 mm bore, 72 mm outer diameter and 12 mm width (1.969 × 2.835 × 0.472 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What internal clearance does 61910-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61910-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61910 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61910-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 50 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 61910?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6910ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×72×12 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61910 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6910ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61910-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61910-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×72×12 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61910-zz",
      "6910zz",
      "61910-ZZ",
      "6910ZZ",
      "61910-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "16010",
    "brand": "NTN",
    "manufacturer_designation": "16010",
    "series": "16000-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 80,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 14.7,
    "static_load_kN": 11.3,
    "fatigue_load_limit_kN": 0.76,
    "limiting_speed_rpm": 8400,
    "max_rpm": 8400,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 16000-series (the narrow extra-light section of ISO 15) the last two digits encode the bore: 16010 carries bore code 10 = 50 mm. Outside diameter 80 mm and width 10 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 50 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 50 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 16010 with C3 for those conditions.",
      "Because the 160xx narrow section shares the 80 mm OD of the 6010 at 50 mm bore but is only 10 mm wide, a housing machined for the wider bearing needs a spacer or relocated circlip — never assume width interchangeability.",
      "The open 16010 has no lubricant retention: grease escapes and contaminants migrate straight into the 50×80×10 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 16000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 16010 units.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 80 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 16010.",
      "The housing bore for the 80 mm OD should be round within IT7; an oval bore pinches the outer ring of 16010 and shows up later as two-point loaded raceway wear.",
      "The open 16010 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 50 mm bore puts 16010 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8400 r/min the grease limiting speed for 16010 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 16010 at 14.7 kN dynamic (C) and 11.3 kN static (C0), 0.76 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 180 g, 16010 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 50×80×10 mm envelope of 16010 gives a D/d ratio of 1.60 and 15.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 14.7/11.3 kN load ratings, 0.76 kN fatigue load limit Cu NTN lists the grease limiting speed at 8400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 180 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 16010 on the 50×80×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 16010 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 16010 bearing?",
        "a": "A 16010 deep-groove ball bearing has a 50 mm bore, 80 mm outer diameter and 10 mm width (1.969 × 3.15 × 0.394 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 16000 compare with other series at the same 50 mm bore?",
        "a": "160 is the narrow extra-light section: 80×10 mm with a 15.0 mm radial section at 50 mm bore. It has the same bore and outside diameter as the 6010 but a narrower ring, so the two are not width-interchangeable; it appears in the manufacturer catalogues used on this site."
      },
      {
        "q": "Are 16010 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 16010 uses the same ISO 15 envelope (50×80×10 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 16010?",
        "a": "NTN lists the open 16010 under the bare designation 16010; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 50 mm bore envelope."
      },
      {
        "q": "Is 16010 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "16010"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6010-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6010",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 80,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 24.2,
    "static_load_kN": 16.6,
    "fatigue_load_limit_kN": 1.24,
    "limiting_speed_rpm": 8400,
    "max_rpm": 8400,
    "weight_g": 261,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6010 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 10 by five gives the 50 mm bore; the 80 mm outside diameter and 16 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 50 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 50 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6010 with C3 for those conditions.",
      "Choosing the 60xx extra-light section saves radial space at 50 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6210 before committing to the smaller envelope.",
      "Storage matters for open bearings: 6010-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 6000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6010 units.",
      "A 50 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Shaft and housing fillets must clear the bearing chamfer so the 16 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "The open 6010 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 50 mm bore puts 6010 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 8400 r/min the grease limiting speed for 6010 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 24.2 kN dynamic load rating (C) and 16.6 kN static (C0), 1.24 kN fatigue load limit Cu, 6010 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 261 g, 6010 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 50×80×16 mm envelope of 6010 gives a D/d ratio of 1.60 and 15.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 24.2/16.6 kN load ratings, 1.24 kN fatigue load limit Cu NTN lists the grease limiting speed at 8400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 261 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6010 on the 50×80×16 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6010 in a rated drive.",
      "Order the C3 internal-clearance version (6010 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6010-NTN bearing?",
        "a": "A 6010-NTN deep-groove ball bearing has a 50 mm bore, 80 mm outer diameter and 16 mm width (1.969 × 3.15 × 0.63 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What does no suffix on 6010 mean?",
        "a": "A bare 6010 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "How does the 6000 compare with other series at the same 50 mm bore?",
        "a": "The second digit is the diameter series: 60 is the smallest standard section (80×16 mm, 15.0 mm radial section) at 50 mm bore — below 62/63/64 in load capacity, for light loads in compact spaces."
      },
      {
        "q": "What is the NTN order number for an open 6010?",
        "a": "NTN lists the open 6010 under the bare designation 6010; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 50 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6010 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6010 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6010-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6010-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6010-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6010",
      "6010-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6010-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6010LLU",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 80,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 24.2,
    "static_load_kN": 16.6,
    "fatigue_load_limit_kN": 1.24,
    "limiting_speed_rpm": 5000,
    "max_rpm": 5000,
    "weight_g": 261,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6010-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 10 by five gives the 50 mm bore; the 80 mm outside diameter and 16 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 50 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6010LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Interference on a 50 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6010 with C3 clearance and re-check the residual value after mounting.",
      "The 60xx extra-light section at 50 mm bore uses a smaller 80 mm OD than a 6210; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "Contact seals add drag and heat: 6010-2RS-NTN runs slower and cooler-limited than the open 6010; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 6010-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6010-2RS-NTN-C3. No clearance suffix means normal CN clearance.",
      "Vibration during standstill brinells the raceways of a 50 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues the contact-sealed version as 6010LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 50 mm bore puts 6010 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5000 r/min the grease limiting speed for 6010 covers medium-duty industrial drives; the contact seal (LLU) is the main speed limiter here — for continuous operation above 80% of this figure use the open variant with an external labyrinth seal and oil bath.",
      "At 24.2 kN dynamic load rating (C) and 16.6 kN static (C0), 1.24 kN fatigue load limit Cu, 6010 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 261 g, 6010 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 50×80×16 mm envelope of 6010 gives a D/d ratio of 1.60 and 15.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 24.2/16.6 kN load ratings, 1.24 kN fatigue load limit Cu NTN lists the grease limiting speed at 5000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 261 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6010LLU on the 50×80×16 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6010 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6010 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6010-2RS-NTN bearing?",
        "a": "A 6010-2RS-NTN deep-groove ball bearing has a 50 mm bore, 80 mm outer diameter and 16 mm width (1.969 × 3.15 × 0.63 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 6000 compare with other series at the same 50 mm bore?",
        "a": "The second digit is the diameter series: 60 is the smallest standard section (80×16 mm, 15.0 mm radial section) at 50 mm bore — below 62/63/64 in load capacity, for light loads in compact spaces."
      },
      {
        "q": "Are 6010 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6010 uses the same ISO 15 envelope (50×80×16 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6010?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6010LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×80×16 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6010LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6010-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6010-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6010-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6010-llu",
      "6010llu",
      "6010-2RS",
      "6010-2rs",
      "6010LLU",
      "6010-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6010-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6010LLB",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 80,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 24.2,
    "static_load_kN": 16.6,
    "fatigue_load_limit_kN": 1.24,
    "limiting_speed_rpm": 6000,
    "max_rpm": 6000,
    "weight_g": 261,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6010-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 10 by five gives the 50 mm bore; the 80 mm outside diameter and 16 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 50 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6010LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Interference on a 50 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6010 with C3 clearance and re-check the residual value after mounting.",
      "The 60xx extra-light section at 50 mm bore uses a smaller 80 mm OD than a 6210; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "The low-drag lip of 6010-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 6010-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 50 mm bore position before relying on it as sealed-for-life.",
      "A 50 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Vibration during standstill brinells the raceways of a 50 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues this low-friction non-contact seal as 6010LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 50 mm bore puts 6010 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6000 r/min the grease limiting speed for 6010 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 24.2 kN dynamic load rating (C) and 16.6 kN static (C0), 1.24 kN fatigue load limit Cu, 6010 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 261 g, 6010 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 50×80×16 mm envelope of 6010 gives a D/d ratio of 1.60 and 15.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 24.2/16.6 kN load ratings, 1.24 kN fatigue load limit Cu NTN lists the grease limiting speed at 6000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 261 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6010LLB on the 50×80×16 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6010 in a rated drive.",
      "Order the C3 internal-clearance version (6010 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6010-RSR-NTN bearing?",
        "a": "A 6010-RSR-NTN deep-groove ball bearing has a 50 mm bore, 80 mm outer diameter and 16 mm width (1.969 × 3.15 × 0.63 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6010 bore code work?",
        "a": "The last two digits of 6010 are bore code 10, giving 10 × 5 = 50 mm bore. The 80 mm outside diameter and 16 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the RSR suffix on 6010-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "What is the NTN suffix for a sealed 6010?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6010LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×80×16 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6010 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6010LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6010-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6010-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6010-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6010-llb",
      "6010llb",
      "6010-RSR",
      "6010-rsr",
      "6010LLB",
      "6010-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6010-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6010ZZ",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 80,
    "B_mm": 16,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 24.2,
    "static_load_kN": 16.6,
    "fatigue_load_limit_kN": 1.24,
    "limiting_speed_rpm": 6000,
    "max_rpm": 6000,
    "weight_g": 261,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6010 carries bore code 10 = 50 mm. Outside diameter 80 mm and width 16 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 50 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6010ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Interference on a 50 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6010 with C3 clearance and re-check the residual value after mounting.",
      "The 60xx extra-light section at 50 mm bore uses a smaller 80 mm OD than a 6210; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "Do not wash 6010-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6010-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Vibration during standstill brinells the raceways of a 50 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Measure the shaft, do not trust the drawing: a 50 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6010-ZZ-NTN.",
      "NTN catalogues the shielded version as 6010ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 50 mm bore puts 6010 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6000 r/min the grease limiting speed for 6010 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 24.2 kN dynamic load rating (C) and 16.6 kN static (C0), 1.24 kN fatigue load limit Cu, 6010 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 261 g, 6010 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 50×80×16 mm envelope of 6010 gives a D/d ratio of 1.60 and 15.0 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 24.2/16.6 kN load ratings, 1.24 kN fatigue load limit Cu NTN lists the grease limiting speed at 6000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 261 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6010ZZ on the 50×80×16 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6010 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Standard catalogue stock of 6010 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6010-ZZ-NTN bearing?",
        "a": "A 6010-ZZ-NTN deep-groove ball bearing has a 50 mm bore, 80 mm outer diameter and 16 mm width (1.969 × 3.15 × 0.63 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 6010-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 6000 compare with other series at the same 50 mm bore?",
        "a": "The second digit is the diameter series: 60 is the smallest standard section (80×16 mm, 15.0 mm radial section) at 50 mm bore — below 62/63/64 in load capacity, for light loads in compact spaces."
      },
      {
        "q": "What is the NTN suffix for a sealed 6010?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6010ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×80×16 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6010ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6010-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6010-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6010-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6010-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×80×16 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6010-zz",
      "6010zz",
      "6010-ZZ",
      "6010ZZ",
      "6010-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6210-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6210",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 90,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 39,
    "static_load_kN": 23.2,
    "fatigue_load_limit_kN": 1.82,
    "limiting_speed_rpm": 7100,
    "max_rpm": 7100,
    "weight_g": 454,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6210 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 10 by five gives the 50 mm bore; the 90 mm outside diameter and 20 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 50 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "At 50 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6210 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 62xx light series is the default general-purpose section at 50 mm bore; before upgrading to a 6310 for extra capacity, confirm the housing accepts a 90 mm OD and 20 mm width — it is not a drop-in swap.",
      "Storage matters for open bearings: 6210-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 6200-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6210 units.",
      "Shaft and housing fillets must clear the bearing chamfer so the 20 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Never mix components between two 6210-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "The open 6210 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 50 mm bore puts 6210 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 7100 r/min the grease limiting speed for 6210 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6210 at 39 kN dynamic (C) and 23.2 kN static (C0), 1.82 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 454 g, 6210 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 50×90×20 mm envelope of 6210 gives a D/d ratio of 1.80 and 20.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 39/23.2 kN load ratings, 1.82 kN fatigue load limit Cu NTN lists the grease limiting speed at 7100 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 454 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6210 on the 50×90×20 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6210 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6210-NTN bearing?",
        "a": "A 6210-NTN deep-groove ball bearing has a 50 mm bore, 90 mm outer diameter and 20 mm width (1.969 × 3.543 × 0.787 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What lubrication does 6210-NTN need?",
        "a": "The open 6210-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "How does the 6210 bore code work?",
        "a": "The last two digits of 6210 are bore code 10, giving 10 × 5 = 50 mm bore. The 90 mm outside diameter and 20 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN order number for an open 6210?",
        "a": "NTN lists the open 6210 under the bare designation 6210; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 50 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6210 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6210 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6210-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6210-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6210-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "210",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "210-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6210",
      "6210-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6210-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6210LLU",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 90,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 39,
    "static_load_kN": 23.2,
    "fatigue_load_limit_kN": 1.82,
    "limiting_speed_rpm": 4700,
    "max_rpm": 4700,
    "weight_g": 454,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6210 carries bore code 10 = 50 mm. Outside diameter 90 mm and width 20 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 50 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6210LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 50 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6210 with C3 for those conditions.",
      "At 50 mm bore the 62xx light series is the workhorse section; its 90×20 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "Contact seals add drag and heat: 6210-2RS-NTN runs slower and cooler-limited than the open 6210; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 6210-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Shaft and housing fillets must clear the bearing chamfer so the 20 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues the contact-sealed version as 6210LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 50 mm bore puts 6210 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN lists the grease limiting speed at 4700 r/min for 6210; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "NTN rates 6210 at 39 kN dynamic (C) and 23.2 kN static (C0), 1.82 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 454 g, 6210 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 50×90×20 mm envelope of 6210 gives a D/d ratio of 1.80 and 20.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 39/23.2 kN load ratings, 1.82 kN fatigue load limit Cu NTN lists the grease limiting speed at 4700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 454 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6210LLU on the 50×90×20 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6210 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6210-2RS-NTN bearing?",
        "a": "A 6210-2RS-NTN deep-groove ball bearing has a 50 mm bore, 90 mm outer diameter and 20 mm width (1.969 × 3.543 × 0.787 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How should 6210-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 50 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6210-2RS-NTN need?",
        "a": "6210-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6210 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 6210?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6210LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×90×20 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6210 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6210LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6210-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6210-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6210-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "210",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "210-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6210-llu",
      "6210llu",
      "6210-2RS",
      "6210-2rs",
      "6210LLU",
      "6210-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6210-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6210LLB",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 90,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 39,
    "static_load_kN": 23.2,
    "fatigue_load_limit_kN": 1.82,
    "limiting_speed_rpm": 5700,
    "max_rpm": 5700,
    "weight_g": 454,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6210-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 10 by five gives the 50 mm bore; the 90 mm outside diameter and 20 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 50 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6210LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "At 50 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6210 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 62xx light series is the default general-purpose section at 50 mm bore; before upgrading to a 6310 for extra capacity, confirm the housing accepts a 90 mm OD and 20 mm width — it is not a drop-in swap.",
      "The low-drag lip of 6210-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 6210-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 50 mm bore position before relying on it as sealed-for-life.",
      "Shaft and housing fillets must clear the bearing chamfer so the 20 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6200-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "NTN catalogues this low-friction non-contact seal as 6210LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 50 mm bore puts 6210 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5700 r/min the grease limiting speed for 6210 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6210 at 39 kN dynamic (C) and 23.2 kN static (C0), 1.82 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 454 g, 6210 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 50×90×20 mm envelope of 6210 gives a D/d ratio of 1.80 and 20.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 39/23.2 kN load ratings, 1.82 kN fatigue load limit Cu NTN lists the grease limiting speed at 5700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 454 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6210LLB on the 50×90×20 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6210 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6210 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6210-RSR-NTN bearing?",
        "a": "A 6210-RSR-NTN deep-groove ball bearing has a 50 mm bore, 90 mm outer diameter and 20 mm width (1.969 × 3.543 × 0.787 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What does the RSR suffix on 6210-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "How does the 6200 compare with other series at the same 50 mm bore?",
        "a": "The '2' is the light diameter series: 90×20 mm with a 20.0 mm radial section at 50 mm bore. A 6310 on the same bore is larger and higher-rated; a 6010 is smaller and lower-rated."
      },
      {
        "q": "What is the NTN suffix for a sealed 6210?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6210LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×90×20 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6210LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6210-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6210-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6210-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "210",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "210-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6210-llb",
      "6210llb",
      "6210-RSR",
      "6210-rsr",
      "6210LLB",
      "6210-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6210-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6210ZZ",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 90,
    "B_mm": 20,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 39,
    "static_load_kN": 23.2,
    "fatigue_load_limit_kN": 1.82,
    "limiting_speed_rpm": 5700,
    "max_rpm": 5700,
    "weight_g": 454,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6210 carries bore code 10 = 50 mm. Outside diameter 90 mm and width 20 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 50 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6210ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 50 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6210 with C3 for those conditions.",
      "At 50 mm bore the 62xx light series is the workhorse section; its 90×20 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "ZZ shields are non-contact: 6210-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6210-2RS for that.",
      "Shielded 6210-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 90 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6210-ZZ-NTN.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 20 mm-wide ring of 6210-ZZ-NTN drags the lip and overheats it.",
      "NTN catalogues the shielded version as 6210ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 50 mm bore puts 6210 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5700 r/min the grease limiting speed for 6210 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6210 at 39 kN dynamic (C) and 23.2 kN static (C0), 1.82 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 454 g, 6210 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 50×90×20 mm envelope of 6210 gives a D/d ratio of 1.80 and 20.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 39/23.2 kN load ratings, 1.82 kN fatigue load limit Cu NTN lists the grease limiting speed at 5700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 454 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6210ZZ on the 50×90×20 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6210 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6210-ZZ-NTN bearing?",
        "a": "A 6210-ZZ-NTN deep-groove ball bearing has a 50 mm bore, 90 mm outer diameter and 20 mm width (1.969 × 3.543 × 0.787 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 6200 compare with other series at the same 50 mm bore?",
        "a": "The '2' is the light diameter series: 90×20 mm with a 20.0 mm radial section at 50 mm bore. A 6310 on the same bore is larger and higher-rated; a 6010 is smaller and lower-rated."
      },
      {
        "q": "Are 6210 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6210 uses the same ISO 15 envelope (50×90×20 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6210?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6210ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×90×20 mm ISO 15 envelope."
      },
      {
        "q": "Is 6210ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6210-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6210-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6210-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "W6210-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "210",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "210-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×90×20 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6210-zz",
      "6210zz",
      "6210-ZZ",
      "6210ZZ",
      "6210-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6310-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6310",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 110,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 68.5,
    "static_load_kN": 38.5,
    "fatigue_load_limit_kN": 2.99,
    "limiting_speed_rpm": 6400,
    "max_rpm": 6400,
    "weight_g": 1070,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6310 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 10 by five gives the 50 mm bore; the 110 mm outside diameter and 27 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 50 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "conveyor drives",
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Interference on a 50 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6310 with C3 clearance and re-check the residual value after mounting.",
      "The 63xx medium section at 50 mm bore gains dynamic rating through larger rolling elements on a 110 mm OD; the penalty is mass and a lower limiting speed than the 6210 — do not specify it for speed-critical shafts.",
      "The open 6310-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 50×110×27 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6310-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "A 50 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Measure the shaft, do not trust the drawing: a 50 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6310-NTN.",
      "The open 6310 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 50 mm bore puts 6310 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 6400 r/min the grease limiting speed for 6310 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6310 at 68.5 kN dynamic (C) and 38.5 kN static (C0), 2.99 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 1070 g (1.1 kg), 6310 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 50×110×27 mm envelope of 6310 gives a D/d ratio of 2.20 and 30.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 68.5/38.5 kN load ratings, 2.99 kN fatigue load limit Cu NTN lists the grease limiting speed at 6400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1070 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6310 on the 50×110×27 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6310 in a rated drive.",
      "Order the C3 internal-clearance version (6310 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6310-NTN bearing?",
        "a": "A 6310-NTN deep-groove ball bearing has a 50 mm bore, 110 mm outer diameter and 27 mm width (1.969 × 4.331 × 1.063 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 6310 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6310 uses the same ISO 15 envelope (50×110×27 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 6310-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6310-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6310 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 6310?",
        "a": "NTN lists the open 6310 under the bare designation 6310; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 50 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6310 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6310 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6310-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "310",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "310-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6310",
      "6310-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6310-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6310LLU",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 110,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 68.5,
    "static_load_kN": 38.5,
    "fatigue_load_limit_kN": 2.99,
    "limiting_speed_rpm": 4200,
    "max_rpm": 4200,
    "weight_g": 1070,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6310 carries bore code 10 = 50 mm. Outside diameter 110 mm and width 27 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 50 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6310LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "conveyor drives",
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "At 50 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6310 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 63xx medium section at 50 mm bore gains dynamic rating through larger rolling elements on a 110 mm OD; the penalty is mass and a lower limiting speed than the 6210 — do not specify it for speed-critical shafts.",
      "Contact seals add drag and heat: 6310-2RS-NTN runs slower and cooler-limited than the open 6310; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 6310-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Measure the shaft, do not trust the drawing: a 50 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6310-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6310LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "The 50 mm bore puts 6310 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "NTN lists the grease limiting speed at 4200 r/min for 6310; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "NTN rates 6310 at 68.5 kN dynamic (C) and 38.5 kN static (C0), 2.99 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 1070 g (1.1 kg), 6310 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 50×110×27 mm envelope of 6310 gives a D/d ratio of 2.20 and 30.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 68.5/38.5 kN load ratings, 2.99 kN fatigue load limit Cu NTN lists the grease limiting speed at 4200 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1070 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6310LLU on the 50×110×27 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6310 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Standard catalogue stock of 6310 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6310-2RS-NTN bearing?",
        "a": "A 6310-2RS-NTN deep-groove ball bearing has a 50 mm bore, 110 mm outer diameter and 27 mm width (1.969 × 4.331 × 1.063 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What does the 2RS suffix on 6310-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "How does the 6300 compare with other series at the same 50 mm bore?",
        "a": "The '3' is the medium diameter series: 110×27 mm, 30.0 mm radial section at 50 mm bore, carrying more load than a 6210 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "What is the NTN suffix for a sealed 6310?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6310LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×110×27 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6310LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6310-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "310",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "310-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6310-llu",
      "6310llu",
      "6310-2RS",
      "6310-2rs",
      "6310LLU",
      "6310-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6310-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6310LLB",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 110,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 68.5,
    "static_load_kN": 38.5,
    "fatigue_load_limit_kN": 2.99,
    "limiting_speed_rpm": 5000,
    "max_rpm": 5000,
    "weight_g": 1070,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6310 carries bore code 10 = 50 mm. Outside diameter 110 mm and width 27 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 50 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6310LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 50 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6310 with C3 for those conditions.",
      "The 63xx medium section at 50 mm bore gains dynamic rating through larger rolling elements on a 110 mm OD; the penalty is mass and a lower limiting speed than the 6210 — do not specify it for speed-critical shafts.",
      "The low-drag lip of 6310-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 6310-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 50 mm bore position before relying on it as sealed-for-life.",
      "Shaft and housing fillets must clear the bearing chamfer so the 27 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 110 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6310-RSR-NTN.",
      "NTN catalogues this low-friction non-contact seal as 6310LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "The 50 mm bore puts 6310 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5000 r/min the grease limiting speed for 6310 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6310 at 68.5 kN dynamic (C) and 38.5 kN static (C0), 2.99 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 1070 g (1.1 kg), 6310 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 50×110×27 mm envelope of 6310 gives a D/d ratio of 2.20 and 30.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 68.5/38.5 kN load ratings, 2.99 kN fatigue load limit Cu NTN lists the grease limiting speed at 5000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1070 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6310LLB on the 50×110×27 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6310 in a rated drive.",
      "Order the C3 internal-clearance version (6310 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6310 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6310-RSR-NTN bearing?",
        "a": "A 6310-RSR-NTN deep-groove ball bearing has a 50 mm bore, 110 mm outer diameter and 27 mm width (1.969 × 4.331 × 1.063 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How should 6310-RSR-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 50 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6310-RSR-NTN need?",
        "a": "6310-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6310 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 6310?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6310LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×110×27 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6310LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6310-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "310",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "310-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6310-llb",
      "6310llb",
      "6310-RSR",
      "6310-rsr",
      "6310LLB",
      "6310-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6310-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6310ZZ",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 110,
    "B_mm": 27,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 68.5,
    "static_load_kN": 38.5,
    "fatigue_load_limit_kN": 2.99,
    "limiting_speed_rpm": 5000,
    "max_rpm": 5000,
    "weight_g": 1070,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6310 carries bore code 10 = 50 mm. Outside diameter 110 mm and width 27 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 50 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6310ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "At 50 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6310 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 63xx medium section at 50 mm bore gains dynamic rating through larger rolling elements on a 110 mm OD; the penalty is mass and a lower limiting speed than the 6210 — do not specify it for speed-critical shafts.",
      "ZZ shields are non-contact: 6310-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6310-2RS for that.",
      "Shielded 6310-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "A 50 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Vibration during standstill brinells the raceways of a 50 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues the shielded version as 6310ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 50 mm bore puts 6310 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5000 r/min the grease limiting speed for 6310 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6310 at 68.5 kN dynamic (C) and 38.5 kN static (C0), 2.99 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 1070 g (1.1 kg), 6310 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 50×110×27 mm envelope of 6310 gives a D/d ratio of 2.20 and 30.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 68.5/38.5 kN load ratings, 2.99 kN fatigue load limit Cu NTN lists the grease limiting speed at 5000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1070 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6310ZZ on the 50×110×27 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6310 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6310 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6310-ZZ-NTN bearing?",
        "a": "A 6310-ZZ-NTN deep-groove ball bearing has a 50 mm bore, 110 mm outer diameter and 27 mm width (1.969 × 4.331 × 1.063 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What lubrication does 6310-ZZ-NTN need?",
        "a": "6310-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "How does the 6310 bore code work?",
        "a": "The last two digits of 6310 are bore code 10, giving 10 × 5 = 50 mm bore. The 110 mm outside diameter and 27 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6310?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6310ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×110×27 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6310ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6310-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6310-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "310",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "310-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×110×27 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6310-zz",
      "6310zz",
      "6310-ZZ",
      "6310ZZ",
      "6310-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6410-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6410",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 92,
    "static_load_kN": 49.5,
    "fatigue_load_limit_kN": 3.85,
    "limiting_speed_rpm": 5700,
    "max_rpm": 5700,
    "weight_g": 1880,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6410 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the heavy 64xx section (diameter series 4 of ISO 15), multiplying bore code 10 by five gives the 50 mm bore; the 130 mm outside diameter and 31 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 50 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Interference on a 50 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6410 with C3 clearance and re-check the residual value after mounting.",
      "The 64xx heavy section at 50 mm bore (130 mm OD) is built for high-load, lower-speed duty; specifying it in a high-rpm motor gives excess heat and short grease life — use 62/63 there.",
      "The open 6410-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 50×130×31 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 6400-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6410 units.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 130 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6410-NTN.",
      "Do not quieten a noisy bearing by preloading it: the 6400-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "The open 6410 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "The 50 mm bore puts 6410 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5700 r/min the grease limiting speed for 6410 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 92 kN dynamic load rating (C) and 49.5 kN static (C0), 3.85 kN fatigue load limit Cu, 6410 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 1880 g (1.9 kg), 6410 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 50×130×31 mm envelope of 6410 gives a D/d ratio of 2.60 and 40.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 92/49.5 kN load ratings, 3.85 kN fatigue load limit Cu NTN lists the grease limiting speed at 5700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1880 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6410 on the 50×130×31 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6410 in a rated drive.",
      "Standard catalogue stock of 6410 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Order the C3 internal-clearance version (6410 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6410-NTN bearing?",
        "a": "A 6410-NTN deep-groove ball bearing has a 50 mm bore, 130 mm outer diameter and 31 mm width (1.969 × 5.118 × 1.22 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6400 compare with other series at the same 50 mm bore?",
        "a": "The '4' is the heavy diameter series: 130×31 mm, 40.0 mm radial section at 50 mm bore — the highest-capacity single-row 6xx option here, aimed at lower-speed, high-load shafts."
      },
      {
        "q": "Are 6410 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6410 uses the same ISO 15 envelope (50×130×31 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 6410?",
        "a": "NTN lists the open 6410 under the bare designation 6410; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 50 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6410?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6410-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 50×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6410",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 50×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6410",
      "6410-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6410-ZZ",
    "brand": "NTN",
    "manufacturer_designation": "6410ZZ",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 50,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 92,
    "static_load_kN": 49.5,
    "fatigue_load_limit_kN": 3.85,
    "limiting_speed_rpm": 5700,
    "max_rpm": 5700,
    "weight_g": 1880,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6400-series (diameter series 4 of ISO 15) the last two digits encode the bore: 6410 carries bore code 10 = 50 mm. Outside diameter 130 mm and width 31 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 50 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6410ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "At 50 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6410 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 64xx heavy section at 50 mm bore exists for high radial load at moderate rpm; its 130 mm OD and 31 mm width demand a larger housing, and grease life at motor speeds is short — treat it as a low-speed, high-load choice.",
      "ZZ shields are non-contact: 6410-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6410-2RS for that.",
      "Do not wash 6410-ZZ in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "A 50 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues the shielded version as 6410ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "The 50 mm bore puts 6410 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.",
      "At 5700 r/min the grease limiting speed for 6410 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 92 kN dynamic load rating (C) and 49.5 kN static (C0), 3.85 kN fatigue load limit Cu, 6410 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 1880 g (1.9 kg), 6410 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 50×130×31 mm envelope of 6410 gives a D/d ratio of 2.60 and 40.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 92/49.5 kN load ratings, 3.85 kN fatigue load limit Cu NTN lists the grease limiting speed at 5700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1880 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6410ZZ on the 50×130×31 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6410 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6410 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6410-ZZ bearing?",
        "a": "A 6410-ZZ deep-groove ball bearing has a 50 mm bore, 130 mm outer diameter and 31 mm width (1.969 × 5.118 × 1.22 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What lubrication does 6410-ZZ need?",
        "a": "6410-ZZ is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "How does the 6410 bore code work?",
        "a": "The last two digits of 6410 are bore code 10, giving 10 × 5 = 50 mm bore. The 130 mm outside diameter and 31 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6410?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6410ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 50×130×31 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6410ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6410-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 50×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6410",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 50×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6410-zz",
      "6410zz",
      "6410-ZZ",
      "6410ZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61811-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6811JR",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 72,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 9.75,
    "static_load_kN": 8.1,
    "fatigue_load_limit_kN": 0.54,
    "limiting_speed_rpm": 8700,
    "max_rpm": 8700,
    "weight_g": 83,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61811 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 11 by five gives the 55 mm bore; the 72 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "At 55 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61811 against the shaft shoulder while it cools so the ring cannot creep back.",
      "Only 8.5 mm of radial section separates bore and OD on the 618xx series at 55 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6211.",
      "The open 61811-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 55×72×9 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 61811-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Vibration during standstill brinells the raceways of a 55 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "The housing bore for the 72 mm OD should be round within IT7; an oval bore pinches the outer ring of 61811-NTN and shows up later as two-point loaded raceway wear.",
      "The open 61811 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 55 mm bore 61811 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 8700 r/min the grease limiting speed for 61811 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61811 at 9.75 kN dynamic (C) and 8.1 kN static (C0), 0.54 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 83 g, 61811 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 55×72×9 mm envelope of 61811 gives a D/d ratio of 1.31 and only 8.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 9.75/8.1 kN load ratings, 0.54 kN fatigue load limit Cu NTN lists the grease limiting speed at 8700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 83 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6811JR on the 55×72×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61811 in a rated drive.",
      "Standard catalogue stock of 61811 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61811 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61811-NTN bearing?",
        "a": "A 61811-NTN deep-groove ball bearing has a 55 mm bore, 72 mm outer diameter and 9 mm width (2.165 × 2.835 × 0.354 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 61811 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61811 uses the same ISO 15 envelope (55×72×9 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 61811-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61811-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61811 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 61811?",
        "a": "NTN lists the open 61811 under the bare designation 6811JR; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 55 mm bore envelope."
      },
      {
        "q": "Does NTN offer 61811 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6811JR is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61811-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6811jr",
      "61811",
      "6811JR",
      "61811-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61811-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6811JRLLU",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 72,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 9.75,
    "static_load_kN": 8.1,
    "fatigue_load_limit_kN": 0.54,
    "limiting_speed_rpm": 4800,
    "max_rpm": 4800,
    "weight_g": 83,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61811-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 11 by five gives the 55 mm bore; the 72 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6811JRLLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Interference on a 55 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61811 with C3 clearance and re-check the residual value after mounting.",
      "The 618xx thin section at 55 mm bore has only a 8.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6211.",
      "Contact seals add drag and heat: 61811-2RS-NTN runs slower and cooler-limited than the open 61811; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 61811-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Never mix components between two 61811-2RS-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "The housing bore for the 72 mm OD should be round within IT7; an oval bore pinches the outer ring of 61811-2RS-NTN and shows up later as two-point loaded raceway wear.",
      "NTN catalogues the contact-sealed version as 6811JRLLU (suffix RLLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 55 mm bore 61811 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4800 r/min for 61811; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "NTN rates 61811 at 9.75 kN dynamic (C) and 8.1 kN static (C0), 0.54 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 83 g, 61811 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 55×72×9 mm envelope of 61811 gives a D/d ratio of 1.31 and only 8.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 9.75/8.1 kN load ratings, 0.54 kN fatigue load limit Cu NTN lists the grease limiting speed at 4800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 83 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6811JRLLU on the 55×72×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61811 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61811-2RS-NTN bearing?",
        "a": "A 61811-2RS-NTN deep-groove ball bearing has a 55 mm bore, 72 mm outer diameter and 9 mm width (2.165 × 2.835 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 61811 bore code work?",
        "a": "The last two digits of 61811 are bore code 11, giving 11 × 5 = 55 mm bore. The 72 mm outside diameter and 9 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the 2RS suffix on 61811-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "What is the NTN suffix for a sealed 61811?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6811JRLLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×72×9 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61811 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6811JRLLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61811-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61811-llu",
      "6811jrllu",
      "6811llu",
      "61811-2RS",
      "61811-2rs",
      "6811JRLLU",
      "61811-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61811-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6811JRLLB",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 72,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 9.75,
    "static_load_kN": 8.1,
    "fatigue_load_limit_kN": 0.54,
    "limiting_speed_rpm": 8700,
    "max_rpm": 8700,
    "weight_g": 83,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61811-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 11 by five gives the 55 mm bore; the 72 mm outside diameter and 9 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6811JRLLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "At 55 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61811 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 618xx thin section at 55 mm bore has only a 8.5 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6211.",
      "The low-drag lip of 61811-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 61811-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 55 mm bore position before relying on it as sealed-for-life.",
      "Measure the shaft, do not trust the drawing: a 55 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61811-RSR-NTN.",
      "Vibration during standstill brinells the raceways of a 55 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues this low-friction non-contact seal as 6811JRLLB (suffix RLLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 55 mm bore 61811 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 8700 r/min the grease limiting speed for 61811 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61811 at 9.75 kN dynamic (C) and 8.1 kN static (C0), 0.54 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 83 g, 61811 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 55×72×9 mm envelope of 61811 gives a D/d ratio of 1.31 and only 8.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 9.75/8.1 kN load ratings, 0.54 kN fatigue load limit Cu NTN lists the grease limiting speed at 8700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 83 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6811JRLLB on the 55×72×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61811 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61811 is listed.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61811-RSR-NTN bearing?",
        "a": "A 61811-RSR-NTN deep-groove ball bearing has a 55 mm bore, 72 mm outer diameter and 9 mm width (2.165 × 2.835 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How should 61811-RSR-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 55 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 61811-RSR-NTN need?",
        "a": "61811-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61811 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 61811?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6811JRLLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×72×9 mm ISO 15 envelope."
      },
      {
        "q": "Is 6811JRLLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61811-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61811-llb",
      "6811jrllb",
      "6811llb",
      "61811-RSR",
      "61811-rsr",
      "6811JRLLB",
      "61811-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61811-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6811JRZZ",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 72,
    "B_mm": 9,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 9.75,
    "static_load_kN": 8.1,
    "fatigue_load_limit_kN": 0.54,
    "limiting_speed_rpm": 8700,
    "max_rpm": 8700,
    "weight_g": 83,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61811 carries bore code 11 = 55 mm. Outside diameter 72 mm and width 9 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 55 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6811JRZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Interference on a 55 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61811 with C3 clearance and re-check the residual value after mounting.",
      "Only 8.5 mm of radial section separates bore and OD on the 618xx series at 55 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6211.",
      "ZZ shields are non-contact: 61811-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61811-2RS for that.",
      "Shielded 61811-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Shaft and housing fillets must clear the bearing chamfer so the 9 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 72 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61811-ZZ-NTN.",
      "NTN catalogues the shielded version as 6811JRZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 55 mm bore 61811 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 8700 r/min the grease limiting speed for 61811 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61811 at 9.75 kN dynamic (C) and 8.1 kN static (C0), 0.54 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 83 g, 61811 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 55×72×9 mm envelope of 61811 gives a D/d ratio of 1.31 and only 8.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 9.75/8.1 kN load ratings, 0.54 kN fatigue load limit Cu NTN lists the grease limiting speed at 8700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 83 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6811JRZZ on the 55×72×9 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61811 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Order the C3 internal-clearance version (61811 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61811-ZZ-NTN bearing?",
        "a": "A 61811-ZZ-NTN deep-groove ball bearing has a 55 mm bore, 72 mm outer diameter and 9 mm width (2.165 × 2.835 × 0.354 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 61811 bore code work?",
        "a": "The last two digits of 61811 are bore code 11, giving 11 × 5 = 55 mm bore. The 72 mm outside diameter and 9 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the ZZ suffix on 61811-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "What is the NTN suffix for a sealed 61811?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6811JRZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×72×9 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61811 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6811JRZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61811-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61811-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×72×9 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61811-zz",
      "6811jrzz",
      "6811zz",
      "61811-ZZ",
      "6811JRZZ",
      "61811-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61911-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6911",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 80,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 17.7,
    "static_load_kN": 13.3,
    "fatigue_load_limit_kN": 0.92,
    "limiting_speed_rpm": 8200,
    "max_rpm": 8200,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61911 carries bore code 11 = 55 mm. Outside diameter 80 mm and width 13 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 55 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Interference on a 55 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61911 with C3 clearance and re-check the residual value after mounting.",
      "The 619xx thin section (12.5 mm section height at 55 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "The open 61911-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 55×80×13 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 61911-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Measure the shaft, do not trust the drawing: a 55 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61911-NTN.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61900-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "The open 61911 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 55 mm bore 61911 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 8200 r/min the grease limiting speed for 61911 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 17.7 kN dynamic load rating (C) and 13.3 kN static (C0), 0.92 kN fatigue load limit Cu, 61911 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 180 g, 61911 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 55×80×13 mm envelope of 61911 gives a D/d ratio of 1.45 and 12.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 17.7/13.3 kN load ratings, 0.92 kN fatigue load limit Cu NTN lists the grease limiting speed at 8200 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 180 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6911 on the 55×80×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61911 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61911 is listed.",
      "Standard catalogue stock of 61911 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61911-NTN bearing?",
        "a": "A 61911-NTN deep-groove ball bearing has a 55 mm bore, 80 mm outer diameter and 13 mm width (2.165 × 3.15 × 0.512 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What internal clearance does 61911-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61911-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61911 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61911-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 55 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN order number for an open 61911?",
        "a": "NTN lists the open 61911 under the bare designation 6911; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 55 mm bore envelope."
      },
      {
        "q": "Does NTN offer 61911 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6911 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61911-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-RSR-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6911",
      "61911",
      "61911-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61911-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6911LLU",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 80,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 17.7,
    "static_load_kN": 13.3,
    "fatigue_load_limit_kN": 0.92,
    "limiting_speed_rpm": 4600,
    "max_rpm": 4600,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61911 carries bore code 11 = 55 mm. Outside diameter 80 mm and width 13 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 55 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6911LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 55 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61911 with C3 for those conditions.",
      "The 619xx thin section at 55 mm bore (12.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "Contact seals add drag and heat: 61911-2RS-NTN runs slower and cooler-limited than the open 61911; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 61911-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "A 55 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues the contact-sealed version as 6911LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 55 mm bore 61911 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4600 r/min for 61911; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "At 17.7 kN dynamic load rating (C) and 13.3 kN static (C0), 0.92 kN fatigue load limit Cu, 61911 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 180 g, 61911 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 55×80×13 mm envelope of 61911 gives a D/d ratio of 1.45 and 12.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 17.7/13.3 kN load ratings, 0.92 kN fatigue load limit Cu NTN lists the grease limiting speed at 4600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 180 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6911LLU on the 55×80×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61911 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61911-2RS-NTN bearing?",
        "a": "A 61911-2RS-NTN deep-groove ball bearing has a 55 mm bore, 80 mm outer diameter and 13 mm width (2.165 × 3.15 × 0.512 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What lubrication does 61911-2RS-NTN need?",
        "a": "61911-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61911 with a housing grease fitting instead."
      },
      {
        "q": "How does the 61911 bore code work?",
        "a": "The last two digits of 61911 are bore code 11, giving 11 × 5 = 55 mm bore. The 80 mm outside diameter and 13 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 61911?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6911LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×80×13 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61911 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6911LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61911-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-RSR-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61911-llu",
      "6911llu",
      "61911-2RS",
      "61911-2rs",
      "6911LLU",
      "61911-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61911-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6911LLB",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 80,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 17.7,
    "static_load_kN": 13.3,
    "fatigue_load_limit_kN": 0.92,
    "limiting_speed_rpm": 5500,
    "max_rpm": 5500,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61911 carries bore code 11 = 55 mm. Outside diameter 80 mm and width 13 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 55 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6911LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "At 55 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61911 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 619xx thin section at 55 mm bore (12.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "RSR low-friction seals on 61911-RSR-NTN run faster than contact-seal 61911-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61911-2RS instead.",
      "The non-contact lip of 61911-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 55 mm bore position before relying on it as sealed-for-life.",
      "Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "The housing bore for the 80 mm OD should be round within IT7; an oval bore pinches the outer ring of 61911-RSR-NTN and shows up later as two-point loaded raceway wear.",
      "NTN catalogues this low-friction non-contact seal as 6911LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 55 mm bore 61911 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 5500 r/min the grease limiting speed for 61911 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 17.7 kN dynamic load rating (C) and 13.3 kN static (C0), 0.92 kN fatigue load limit Cu, 61911 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 180 g, 61911 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 55×80×13 mm envelope of 61911 gives a D/d ratio of 1.45 and 12.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 17.7/13.3 kN load ratings, 0.92 kN fatigue load limit Cu NTN lists the grease limiting speed at 5500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 180 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6911LLB on the 55×80×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61911 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61911 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61911-RSR-NTN bearing?",
        "a": "A 61911-RSR-NTN deep-groove ball bearing has a 55 mm bore, 80 mm outer diameter and 13 mm width (2.165 × 3.15 × 0.512 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What does the RSR suffix on 61911-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "How does the 61900 compare with other series at the same 55 mm bore?",
        "a": "619 is a thin section one step above 618: 80×13 mm with a 12.5 mm radial section at 55 mm bore; a 6211 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "What is the NTN suffix for a sealed 61911?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6911LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×80×13 mm ISO 15 envelope."
      },
      {
        "q": "Is 6911LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61911-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-RSR-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61911-llb",
      "6911llb",
      "61911-RSR",
      "61911-rsr",
      "6911LLB",
      "61911-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61911-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6911ZZ",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 80,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 17.7,
    "static_load_kN": 13.3,
    "fatigue_load_limit_kN": 0.92,
    "limiting_speed_rpm": 5500,
    "max_rpm": 5500,
    "weight_g": 180,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61911 carries bore code 11 = 55 mm. Outside diameter 80 mm and width 13 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 55 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6911ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Interference on a 55 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61911 with C3 clearance and re-check the residual value after mounting.",
      "The 619xx thin section at 55 mm bore (12.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "ZZ shields are non-contact: 61911-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61911-2RS for that.",
      "Do not wash 61911-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 13 mm-wide ring of 61911-ZZ-NTN drags the lip and overheats it.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61900-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "NTN catalogues the shielded version as 6911ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 55 mm bore 61911 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 5500 r/min the grease limiting speed for 61911 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 17.7 kN dynamic load rating (C) and 13.3 kN static (C0), 0.92 kN fatigue load limit Cu, 61911 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 180 g, 61911 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 55×80×13 mm envelope of 61911 gives a D/d ratio of 1.45 and 12.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 17.7/13.3 kN load ratings, 0.92 kN fatigue load limit Cu NTN lists the grease limiting speed at 5500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 180 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6911ZZ on the 55×80×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61911 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61911 is listed.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61911-ZZ-NTN bearing?",
        "a": "A 61911-ZZ-NTN deep-groove ball bearing has a 55 mm bore, 80 mm outer diameter and 13 mm width (2.165 × 3.15 × 0.512 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What internal clearance does 61911-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61911-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61911 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 61911-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 55 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 61911?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6911ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×80×13 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6911ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61911-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-RSR-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61911-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×80×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61911-zz",
      "6911zz",
      "61911-ZZ",
      "6911ZZ",
      "61911-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "16011-NTN",
    "brand": "NTN",
    "manufacturer_designation": "16011",
    "series": "16000-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 90,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 20.6,
    "static_load_kN": 15.3,
    "fatigue_load_limit_kN": 1.06,
    "limiting_speed_rpm": 7700,
    "max_rpm": 7700,
    "weight_g": 258,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "16011 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the narrow 160xx section of the ISO 15 general plan, multiplying bore code 11 by five gives the 55 mm bore; the 90 mm outside diameter and 11 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "At 55 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 16011 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 160xx narrow section at 55 mm bore shares the 90 mm outside diameter of the 6011 but is only 11 mm wide; a 6011 in an 11 mm-wide seat is loose axially and the reverse swap will not fit — match width as well as bore and outside diameter.",
      "The open 16011-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 55×90×11 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 16011-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Shaft and housing fillets must clear the bearing chamfer so the 11 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Vibration during standstill brinells the raceways of a 55 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "The open 16011 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 55 mm bore 16011 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7700 r/min the grease limiting speed for 16011 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 20.6 kN dynamic load rating (C) and 15.3 kN static (C0), 1.06 kN fatigue load limit Cu, 16011 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 258 g, 16011 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 55×90×11 mm envelope of 16011 gives a D/d ratio of 1.64 and 17.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 20.6/15.3 kN load ratings, 1.06 kN fatigue load limit Cu NTN lists the grease limiting speed at 7700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 258 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 16011 on the 55×90×11 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 16011 in a rated drive.",
      "Order the C3 internal-clearance version (16011 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Standard catalogue stock of 16011 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 16011-NTN bearing?",
        "a": "A 16011-NTN deep-groove ball bearing has a 55 mm bore, 90 mm outer diameter and 11 mm width (2.165 × 3.543 × 0.433 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What does no suffix on 16011 mean?",
        "a": "A bare 16011 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "How does the 16000 compare with other series at the same 55 mm bore?",
        "a": "160 is the narrow extra-light section: 90×11 mm with a 17.5 mm radial section at 55 mm bore. It has the same bore and outside diameter as the 6011 but a narrower ring, so the two are not width-interchangeable; it appears in the manufacturer catalogues used on this site."
      },
      {
        "q": "What is the NTN order number for an open 16011?",
        "a": "NTN lists the open 16011 under the bare designation 16011; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 55 mm bore envelope."
      },
      {
        "q": "Does NTN offer 16011 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 16011 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "16011",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 55×90×11 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "16011",
      "16011-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6011-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6011",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 90,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 31.5,
    "static_load_kN": 21.2,
    "fatigue_load_limit_kN": 1.62,
    "limiting_speed_rpm": 7700,
    "max_rpm": 7700,
    "weight_g": 388,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6011 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 11 by five gives the 55 mm bore; the 90 mm outside diameter and 18 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 55 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6011 with C3 for those conditions.",
      "The 60xx extra-light section at 55 mm bore uses a smaller 90 mm OD than a 6211; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "Storage matters for open bearings: 6011-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 6000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6011 units.",
      "Shaft and housing fillets must clear the bearing chamfer so the 18 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Do not quieten a noisy bearing by preloading it: the 6000-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "The open 6011 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 55 mm bore 6011 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7700 r/min the grease limiting speed for 6011 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 31.5 kN dynamic load rating (C) and 21.2 kN static (C0), 1.62 kN fatigue load limit Cu, 6011 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 388 g, 6011 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 55×90×18 mm envelope of 6011 gives a D/d ratio of 1.64 and 17.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 31.5/21.2 kN load ratings, 1.62 kN fatigue load limit Cu NTN lists the grease limiting speed at 7700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 388 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6011 on the 55×90×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6011 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6011 is listed.",
      "Order the C3 internal-clearance version (6011 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6011-NTN bearing?",
        "a": "A 6011-NTN deep-groove ball bearing has a 55 mm bore, 90 mm outer diameter and 18 mm width (2.165 × 3.543 × 0.709 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What lubrication does 6011-NTN need?",
        "a": "The open 6011-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "How does the 6011 bore code work?",
        "a": "The last two digits of 6011 are bore code 11, giving 11 × 5 = 55 mm bore. The 90 mm outside diameter and 18 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN order number for an open 6011?",
        "a": "NTN lists the open 6011 under the bare designation 6011; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 55 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6011 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6011 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6011-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6011",
      "6011-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6011-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6011LLU",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 90,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 31.5,
    "static_load_kN": 21.2,
    "fatigue_load_limit_kN": 1.62,
    "limiting_speed_rpm": 4500,
    "max_rpm": 4500,
    "weight_g": 388,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6011 carries bore code 11 = 55 mm. Outside diameter 90 mm and width 18 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 55 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6011LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At 55 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6011 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 60xx extra-light section at 55 mm bore uses a smaller 90 mm OD than a 6211; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "Contact seals add drag and heat: 6011-2RS-NTN runs slower and cooler-limited than the open 6011; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 6011-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Vibration during standstill brinells the raceways of a 55 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Measure the shaft, do not trust the drawing: a 55 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6011-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6011LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 55 mm bore 6011 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4500 r/min for 6011; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "At 31.5 kN dynamic load rating (C) and 21.2 kN static (C0), 1.62 kN fatigue load limit Cu, 6011 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 388 g, 6011 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 55×90×18 mm envelope of 6011 gives a D/d ratio of 1.64 and 17.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 31.5/21.2 kN load ratings, 1.62 kN fatigue load limit Cu NTN lists the grease limiting speed at 4500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 388 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6011LLU on the 55×90×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6011 in a rated drive.",
      "Standard catalogue stock of 6011 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6011-2RS-NTN bearing?",
        "a": "A 6011-2RS-NTN deep-groove ball bearing has a 55 mm bore, 90 mm outer diameter and 18 mm width (2.165 × 3.543 × 0.709 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How does the 6011 bore code work?",
        "a": "The last two digits of 6011 are bore code 11, giving 11 × 5 = 55 mm bore. The 90 mm outside diameter and 18 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the 2RS suffix on 6011-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "What is the NTN suffix for a sealed 6011?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6011LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×90×18 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6011 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6011LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6011-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6011-llu",
      "6011llu",
      "6011-2RS",
      "6011-2rs",
      "6011LLU",
      "6011-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6011-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6011LLB",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 90,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 31.5,
    "static_load_kN": 21.2,
    "fatigue_load_limit_kN": 1.62,
    "limiting_speed_rpm": 7700,
    "max_rpm": 7700,
    "weight_g": 388,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6011-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 11 by five gives the 55 mm bore; the 90 mm outside diameter and 18 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6011LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 55 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6011 with C3 for those conditions.",
      "The 60xx extra-light section at 55 mm bore uses a smaller 90 mm OD than a 6211; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "The low-drag lip of 6011-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 6011-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 55 mm bore position before relying on it as sealed-for-life.",
      "Measure the shaft, do not trust the drawing: a 55 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6011-RSR-NTN.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues this low-friction non-contact seal as 6011LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 55 mm bore 6011 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7700 r/min the grease limiting speed for 6011 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 31.5 kN dynamic load rating (C) and 21.2 kN static (C0), 1.62 kN fatigue load limit Cu, 6011 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 388 g, 6011 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 55×90×18 mm envelope of 6011 gives a D/d ratio of 1.64 and 17.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 31.5/21.2 kN load ratings, 1.62 kN fatigue load limit Cu NTN lists the grease limiting speed at 7700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 388 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6011LLB on the 55×90×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6011 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6011-RSR-NTN bearing?",
        "a": "A 6011-RSR-NTN deep-groove ball bearing has a 55 mm bore, 90 mm outer diameter and 18 mm width (2.165 × 3.543 × 0.709 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6000 compare with other series at the same 55 mm bore?",
        "a": "The second digit is the diameter series: 60 is the smallest standard section (90×18 mm, 17.5 mm radial section) at 55 mm bore — below 62/63/64 in load capacity, for light loads in compact spaces."
      },
      {
        "q": "Are 6011 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6011 uses the same ISO 15 envelope (55×90×18 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6011?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6011LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×90×18 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6011 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6011LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6011-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6011-llb",
      "6011llb",
      "6011-RSR",
      "6011-rsr",
      "6011LLB",
      "6011-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6011-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6011ZZ",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 90,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 31.5,
    "static_load_kN": 21.2,
    "fatigue_load_limit_kN": 1.62,
    "limiting_speed_rpm": 7700,
    "max_rpm": 7700,
    "weight_g": 388,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6011-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 11 by five gives the 55 mm bore; the 90 mm outside diameter and 18 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6011ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 55 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6011 with C3 for those conditions.",
      "Choosing the 60xx extra-light section saves radial space at 55 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6211 before committing to the smaller envelope.",
      "ZZ shields are non-contact: 6011-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6011-2RS for that.",
      "Shielded 6011-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "A 55 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "The housing bore for the 90 mm OD should be round within IT7; an oval bore pinches the outer ring of 6011-ZZ-NTN and shows up later as two-point loaded raceway wear.",
      "NTN catalogues the shielded version as 6011ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 55 mm bore 6011 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7700 r/min the grease limiting speed for 6011 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 31.5 kN dynamic load rating (C) and 21.2 kN static (C0), 1.62 kN fatigue load limit Cu, 6011 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 388 g, 6011 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 55×90×18 mm envelope of 6011 gives a D/d ratio of 1.64 and 17.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 31.5/21.2 kN load ratings, 1.62 kN fatigue load limit Cu NTN lists the grease limiting speed at 7700 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 388 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6011ZZ on the 55×90×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6011 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Order the C3 internal-clearance version (6011 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6011-ZZ-NTN bearing?",
        "a": "A 6011-ZZ-NTN deep-groove ball bearing has a 55 mm bore, 90 mm outer diameter and 18 mm width (2.165 × 3.543 × 0.709 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How should 6011-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 55 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6011-ZZ-NTN need?",
        "a": "6011-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "What is the NTN suffix for a sealed 6011?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6011ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×90×18 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6011ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6011-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6011-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×90×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6011-zz",
      "6011zz",
      "6011-ZZ",
      "6011ZZ",
      "6011-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6211-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6211",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 100,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 48,
    "static_load_kN": 29.2,
    "fatigue_load_limit_kN": 2.29,
    "limiting_speed_rpm": 6400,
    "max_rpm": 6400,
    "weight_g": 601,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6211 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 11 by five gives the 55 mm bore; the 100 mm outside diameter and 21 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "conveyor drives",
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "At 55 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6211 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 62xx light series is the default general-purpose section at 55 mm bore; before upgrading to a 6311 for extra capacity, confirm the housing accepts a 100 mm OD and 21 mm width — it is not a drop-in swap.",
      "Storage matters for open bearings: 6211-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 6200-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6211 units.",
      "Never mix components between two 6211-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Do not quieten a noisy bearing by preloading it: the 6200-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "The open 6211 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 55 mm bore 6211 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 6400 r/min the grease limiting speed for 6211 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6211 at 48 kN dynamic (C) and 29.2 kN static (C0), 2.29 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 601 g, 6211 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 55×100×21 mm envelope of 6211 gives a D/d ratio of 1.82 and 22.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 48/29.2 kN load ratings, 2.29 kN fatigue load limit Cu NTN lists the grease limiting speed at 6400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 601 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6211 on the 55×100×21 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6211 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6211 is listed.",
      "Standard catalogue stock of 6211 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6211-NTN bearing?",
        "a": "A 6211-NTN deep-groove ball bearing has a 55 mm bore, 100 mm outer diameter and 21 mm width (2.165 × 3.937 × 0.827 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6200 compare with other series at the same 55 mm bore?",
        "a": "The '2' is the light diameter series: 100×21 mm with a 22.5 mm radial section at 55 mm bore. A 6311 on the same bore is larger and higher-rated; a 6011 is smaller and lower-rated."
      },
      {
        "q": "Are 6211 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6211 uses the same ISO 15 envelope (55×100×21 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 6211?",
        "a": "NTN lists the open 6211 under the bare designation 6211; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 55 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6211?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6211-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "211",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "211-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6211",
      "6211-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6211-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6211LLU",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 100,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 48,
    "static_load_kN": 29.2,
    "fatigue_load_limit_kN": 2.29,
    "limiting_speed_rpm": 4300,
    "max_rpm": 4300,
    "weight_g": 601,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6211-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 11 by five gives the 55 mm bore; the 100 mm outside diameter and 21 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6211LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 55 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6211 with C3 for those conditions.",
      "The 62xx light series is the default general-purpose section at 55 mm bore; before upgrading to a 6311 for extra capacity, confirm the housing accepts a 100 mm OD and 21 mm width — it is not a drop-in swap.",
      "Contact seals add drag and heat: 6211-2RS-NTN runs slower and cooler-limited than the open 6211; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 6211-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "The housing bore for the 100 mm OD should be round within IT7; an oval bore pinches the outer ring of 6211-2RS-NTN and shows up later as two-point loaded raceway wear.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 21 mm-wide ring of 6211-2RS-NTN drags the lip and overheats it.",
      "NTN catalogues the contact-sealed version as 6211LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 55 mm bore 6211 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4300 r/min for 6211; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "NTN rates 6211 at 48 kN dynamic (C) and 29.2 kN static (C0), 2.29 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 601 g, 6211 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 55×100×21 mm envelope of 6211 gives a D/d ratio of 1.82 and 22.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 48/29.2 kN load ratings, 2.29 kN fatigue load limit Cu NTN lists the grease limiting speed at 4300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 601 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6211LLU on the 55×100×21 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6211 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6211-2RS-NTN bearing?",
        "a": "A 6211-2RS-NTN deep-groove ball bearing has a 55 mm bore, 100 mm outer diameter and 21 mm width (2.165 × 3.937 × 0.827 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What internal clearance does 6211-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6211-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6211 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6211-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 55 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 6211?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6211LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×100×21 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6211 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6211LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6211-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "211",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "211-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6211-llu",
      "6211llu",
      "6211-2RS",
      "6211-2rs",
      "6211LLU",
      "6211-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6211-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6211LLB",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 100,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 48,
    "static_load_kN": 29.2,
    "fatigue_load_limit_kN": 2.29,
    "limiting_speed_rpm": 6400,
    "max_rpm": 6400,
    "weight_g": 601,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6211-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 11 by five gives the 55 mm bore; the 100 mm outside diameter and 21 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6211LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 55 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6211 with C3 for those conditions.",
      "At 55 mm bore the 62xx light series is the workhorse section; its 100×21 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "RSR low-friction seals on 6211-RSR-NTN run faster than contact-seal 6211-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6211-2RS instead.",
      "The non-contact lip of 6211-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 55 mm bore position before relying on it as sealed-for-life.",
      "Do not quieten a noisy bearing by preloading it: the 6200-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues this low-friction non-contact seal as 6211LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 55 mm bore 6211 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 6400 r/min the grease limiting speed for 6211 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6211 at 48 kN dynamic (C) and 29.2 kN static (C0), 2.29 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 601 g, 6211 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 55×100×21 mm envelope of 6211 gives a D/d ratio of 1.82 and 22.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 48/29.2 kN load ratings, 2.29 kN fatigue load limit Cu NTN lists the grease limiting speed at 6400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 601 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6211LLB on the 55×100×21 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6211 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Order the C3 internal-clearance version (6211 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6211-RSR-NTN bearing?",
        "a": "A 6211-RSR-NTN deep-groove ball bearing has a 55 mm bore, 100 mm outer diameter and 21 mm width (2.165 × 3.937 × 0.827 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What does the RSR suffix on 6211-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "How does the 6200 compare with other series at the same 55 mm bore?",
        "a": "The '2' is the light diameter series: 100×21 mm with a 22.5 mm radial section at 55 mm bore. A 6311 on the same bore is larger and higher-rated; a 6011 is smaller and lower-rated."
      },
      {
        "q": "What is the NTN suffix for a sealed 6211?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6211LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×100×21 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6211 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6211LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6211-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "211",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "211-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6211-llb",
      "6211llb",
      "6211-RSR",
      "6211-rsr",
      "6211LLB",
      "6211-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6211-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6211ZZ",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 100,
    "B_mm": 21,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 48,
    "static_load_kN": 29.2,
    "fatigue_load_limit_kN": 2.29,
    "limiting_speed_rpm": 6400,
    "max_rpm": 6400,
    "weight_g": 601,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6211 carries bore code 11 = 55 mm. Outside diameter 100 mm and width 21 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 55 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6211ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "conveyor drives",
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 55 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6211 with C3 for those conditions.",
      "The 62xx light series is the default general-purpose section at 55 mm bore; before upgrading to a 6311 for extra capacity, confirm the housing accepts a 100 mm OD and 21 mm width — it is not a drop-in swap.",
      "Do not wash 6211-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6211-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6200-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "A 55 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues the shielded version as 6211ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 55 mm bore 6211 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 6400 r/min the grease limiting speed for 6211 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6211 at 48 kN dynamic (C) and 29.2 kN static (C0), 2.29 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 601 g, 6211 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 55×100×21 mm envelope of 6211 gives a D/d ratio of 1.82 and 22.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 48/29.2 kN load ratings, 2.29 kN fatigue load limit Cu NTN lists the grease limiting speed at 6400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 601 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6211ZZ on the 55×100×21 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6211 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6211-ZZ-NTN bearing?",
        "a": "A 6211-ZZ-NTN deep-groove ball bearing has a 55 mm bore, 100 mm outer diameter and 21 mm width (2.165 × 3.937 × 0.827 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 6211 bore code work?",
        "a": "The last two digits of 6211 are bore code 11, giving 11 × 5 = 55 mm bore. The 100 mm outside diameter and 21 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the ZZ suffix on 6211-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "What is the NTN suffix for a sealed 6211?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6211ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×100×21 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6211ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6211-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6211-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "211",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "211-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×100×21 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6211-zz",
      "6211zz",
      "6211-ZZ",
      "6211ZZ",
      "6211-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6311-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6311",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 120,
    "B_mm": 29,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 79.5,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 3.5,
    "limiting_speed_rpm": 5800,
    "max_rpm": 5800,
    "weight_g": 1370,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6311 carries bore code 11 = 55 mm. Outside diameter 120 mm and width 29 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 55 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "conveyor drives",
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 55 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6311 with C3 for those conditions.",
      "The 63xx medium series gains rating at 55 mm bore through a 120 mm OD and 29 mm width; the heavier rolling elements also trade away some speed versus a 6211.",
      "The open 6311-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 55×120×29 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 6300-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6311 units.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 120 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6311-NTN.",
      "Never mix components between two 6311-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "The open 6311 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 55 mm bore 6311 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 5800 r/min the grease limiting speed for 6311 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 79.5 kN dynamic load rating (C) and 45 kN static (C0), 3.5 kN fatigue load limit Cu, 6311 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 1370 g (1.4 kg), 6311 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 55×120×29 mm envelope of 6311 gives a D/d ratio of 2.18 and 32.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 79.5/45 kN load ratings, 3.5 kN fatigue load limit Cu NTN lists the grease limiting speed at 5800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1370 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6311 on the 55×120×29 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6311 in a rated drive.",
      "Order the C3 internal-clearance version (6311 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6311-NTN bearing?",
        "a": "A 6311-NTN deep-groove ball bearing has a 55 mm bore, 120 mm outer diameter and 29 mm width (2.165 × 4.724 × 1.142 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What internal clearance does 6311-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6311-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6311 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6311-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 55 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN order number for an open 6311?",
        "a": "NTN lists the open 6311 under the bare designation 6311; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 55 mm bore envelope."
      },
      {
        "q": "Is 6311 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6311-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "311",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "311-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6311",
      "6311-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6311-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6311LLU",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 120,
    "B_mm": 29,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 79.5,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 3.5,
    "limiting_speed_rpm": 3900,
    "max_rpm": 3900,
    "weight_g": 1370,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6311 carries bore code 11 = 55 mm. Outside diameter 120 mm and width 29 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 55 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6311LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Interference on a 55 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6311 with C3 clearance and re-check the residual value after mounting.",
      "The 63xx medium section at 55 mm bore gains dynamic rating through larger rolling elements on a 120 mm OD; the penalty is mass and a lower limiting speed than the 6211 — do not specify it for speed-critical shafts.",
      "Heat is the enemy of the sealed 6311-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 6311-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Do not quieten a noisy bearing by preloading it: the 6300-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "The housing bore for the 120 mm OD should be round within IT7; an oval bore pinches the outer ring of 6311-2RS-NTN and shows up later as two-point loaded raceway wear.",
      "NTN catalogues the contact-sealed version as 6311LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 55 mm bore 6311 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 3900 r/min for 6311; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "At 79.5 kN dynamic load rating (C) and 45 kN static (C0), 3.5 kN fatigue load limit Cu, 6311 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 1370 g (1.4 kg), 6311 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 55×120×29 mm envelope of 6311 gives a D/d ratio of 2.18 and 32.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 79.5/45 kN load ratings, 3.5 kN fatigue load limit Cu NTN lists the grease limiting speed at 3900 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1370 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6311LLU on the 55×120×29 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6311 in a rated drive.",
      "Order the C3 internal-clearance version (6311 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6311-2RS-NTN bearing?",
        "a": "A 6311-2RS-NTN deep-groove ball bearing has a 55 mm bore, 120 mm outer diameter and 29 mm width (2.165 × 4.724 × 1.142 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How should 6311-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 55 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6311-2RS-NTN need?",
        "a": "6311-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6311 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 6311?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6311LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×120×29 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6311 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6311LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6311-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "311",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "311-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6311-llu",
      "6311llu",
      "6311-2RS",
      "6311-2rs",
      "6311LLU",
      "6311-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6311-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6311LLB",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 120,
    "B_mm": 29,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 79.5,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 3.5,
    "limiting_speed_rpm": 5800,
    "max_rpm": 5800,
    "weight_g": 1370,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6311-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 11 by five gives the 55 mm bore; the 120 mm outside diameter and 29 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6311LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 55 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6311 with C3 for those conditions.",
      "The 63xx medium series gains rating at 55 mm bore through a 120 mm OD and 29 mm width; the heavier rolling elements also trade away some speed versus a 6211.",
      "The low-drag lip of 6311-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 6311-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 55 mm bore position before relying on it as sealed-for-life.",
      "A 55 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "The housing bore for the 120 mm OD should be round within IT7; an oval bore pinches the outer ring of 6311-RSR-NTN and shows up later as two-point loaded raceway wear.",
      "NTN catalogues this low-friction non-contact seal as 6311LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 55 mm bore 6311 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 5800 r/min the grease limiting speed for 6311 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 79.5 kN dynamic load rating (C) and 45 kN static (C0), 3.5 kN fatigue load limit Cu, 6311 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 1370 g (1.4 kg), 6311 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 55×120×29 mm envelope of 6311 gives a D/d ratio of 2.18 and 32.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 79.5/45 kN load ratings, 3.5 kN fatigue load limit Cu NTN lists the grease limiting speed at 5800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1370 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6311LLB on the 55×120×29 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6311 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Standard catalogue stock of 6311 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6311-RSR-NTN bearing?",
        "a": "A 6311-RSR-NTN deep-groove ball bearing has a 55 mm bore, 120 mm outer diameter and 29 mm width (2.165 × 4.724 × 1.142 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6300 compare with other series at the same 55 mm bore?",
        "a": "The '3' is the medium diameter series: 120×29 mm, 32.5 mm radial section at 55 mm bore, carrying more load than a 6211 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "Are 6311 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6311 uses the same ISO 15 envelope (55×120×29 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6311?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6311LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×120×29 mm ISO 15 envelope."
      },
      {
        "q": "Is 6311LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6311-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "311",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "311-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6311-llb",
      "6311llb",
      "6311-RSR",
      "6311-rsr",
      "6311LLB",
      "6311-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6311-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6311ZZ",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 120,
    "B_mm": 29,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 79.5,
    "static_load_kN": 45,
    "fatigue_load_limit_kN": 3.5,
    "limiting_speed_rpm": 5800,
    "max_rpm": 5800,
    "weight_g": 1370,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6311-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 11 by five gives the 55 mm bore; the 120 mm outside diameter and 29 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6311ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "At 55 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6311 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 63xx medium section at 55 mm bore gains dynamic rating through larger rolling elements on a 120 mm OD; the penalty is mass and a lower limiting speed than the 6211 — do not specify it for speed-critical shafts.",
      "Do not wash 6311-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 6311-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Do not quieten a noisy bearing by preloading it: the 6300-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 120 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6311-ZZ-NTN.",
      "NTN catalogues the shielded version as 6311ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 55 mm bore 6311 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 5800 r/min the grease limiting speed for 6311 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 79.5 kN dynamic load rating (C) and 45 kN static (C0), 3.5 kN fatigue load limit Cu, 6311 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 1370 g (1.4 kg), 6311 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 55×120×29 mm envelope of 6311 gives a D/d ratio of 2.18 and 32.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 79.5/45 kN load ratings, 3.5 kN fatigue load limit Cu NTN lists the grease limiting speed at 5800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1370 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6311ZZ on the 55×120×29 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6311 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6311-ZZ-NTN bearing?",
        "a": "A 6311-ZZ-NTN deep-groove ball bearing has a 55 mm bore, 120 mm outer diameter and 29 mm width (2.165 × 4.724 × 1.142 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How should 6311-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 55 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6311-ZZ-NTN need?",
        "a": "6311-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "What is the NTN suffix for a sealed 6311?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6311ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×120×29 mm ISO 15 envelope."
      },
      {
        "q": "Is 6311ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6311-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-2RS-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-ZZ-FAG",
        "equiv_brand": "FAG",
        "level": "full",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6311-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "311",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "311-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×120×29 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6311-zz",
      "6311zz",
      "6311-ZZ",
      "6311ZZ",
      "6311-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6411-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6411",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 98.5,
    "static_load_kN": 54,
    "fatigue_load_limit_kN": 4.2,
    "limiting_speed_rpm": 5200,
    "max_rpm": 5200,
    "weight_g": 2290,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6411 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the heavy 64xx section (diameter series 4 of ISO 15), multiplying bore code 11 by five gives the 55 mm bore; the 140 mm outside diameter and 33 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Interference on a 55 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6411 with C3 clearance and re-check the residual value after mounting.",
      "The 64xx heavy section at 55 mm bore (140 mm OD) is built for high-load, lower-speed duty; specifying it in a high-rpm motor gives excess heat and short grease life — use 62/63 there.",
      "The open 6411-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 55×140×33 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6411-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "A 55 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6400-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "The open 6411 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 55 mm bore 6411 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 5200 r/min the grease limiting speed for 6411 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 98.5 kN dynamic load rating (C) and 54 kN static (C0), 4.2 kN fatigue load limit Cu, 6411 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 2290 g (2.3 kg), 6411 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 55×140×33 mm envelope of 6411 gives a D/d ratio of 2.55 and 42.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 98.5/54 kN load ratings, 4.2 kN fatigue load limit Cu NTN lists the grease limiting speed at 5200 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 2290 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6411 on the 55×140×33 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6411 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6411-NTN bearing?",
        "a": "A 6411-NTN deep-groove ball bearing has a 55 mm bore, 140 mm outer diameter and 33 mm width (2.165 × 5.512 × 1.299 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What does no suffix on 6411 mean?",
        "a": "A bare 6411 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "How does the 6400 compare with other series at the same 55 mm bore?",
        "a": "The '4' is the heavy diameter series: 140×33 mm, 42.5 mm radial section at 55 mm bore — the highest-capacity single-row 6xx option here, aimed at lower-speed, high-load shafts."
      },
      {
        "q": "What is the NTN order number for an open 6411?",
        "a": "NTN lists the open 6411 under the bare designation 6411; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 55 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6411 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6411 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6411-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6411-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 55×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6411",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6411",
      "6411-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6411-ZZ",
    "brand": "NTN",
    "manufacturer_designation": "6411ZZ",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 55,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 98.5,
    "static_load_kN": 54,
    "fatigue_load_limit_kN": 4.2,
    "limiting_speed_rpm": 5200,
    "max_rpm": 5200,
    "weight_g": 2290,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6411-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the heavy 64xx section (diameter series 4 of ISO 15), multiplying bore code 11 by five gives the 55 mm bore; the 140 mm outside diameter and 33 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 55 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6411ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Interference on a 55 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6411 with C3 clearance and re-check the residual value after mounting.",
      "The 64xx heavy section at 55 mm bore exists for high radial load at moderate rpm; its 140 mm OD and 33 mm width demand a larger housing, and grease life at motor speeds is short — treat it as a low-speed, high-load choice.",
      "ZZ shields are non-contact: 6411-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6411-2RS for that.",
      "Do not wash 6411-ZZ in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 33 mm-wide ring of 6411-ZZ drags the lip and overheats it.",
      "Do not quieten a noisy bearing by preloading it: the 6400-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues the shielded version as 6411ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 55 mm bore 6411 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 5200 r/min the grease limiting speed for 6411 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 98.5 kN dynamic load rating (C) and 54 kN static (C0), 4.2 kN fatigue load limit Cu, 6411 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 2290 g (2.3 kg), 6411 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 55×140×33 mm envelope of 6411 gives a D/d ratio of 2.55 and 42.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 98.5/54 kN load ratings, 4.2 kN fatigue load limit Cu NTN lists the grease limiting speed at 5200 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 2290 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6411ZZ on the 55×140×33 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6411 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6411-ZZ bearing?",
        "a": "A 6411-ZZ deep-groove ball bearing has a 55 mm bore, 140 mm outer diameter and 33 mm width (2.165 × 5.512 × 1.299 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 6400 compare with other series at the same 55 mm bore?",
        "a": "The '4' is the heavy diameter series: 140×33 mm, 42.5 mm radial section at 55 mm bore — the highest-capacity single-row 6xx option here, aimed at lower-speed, high-load shafts."
      },
      {
        "q": "Are 6411 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6411 uses the same ISO 15 envelope (55×140×33 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6411?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6411ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 55×140×33 mm ISO 15 envelope."
      },
      {
        "q": "Is 6411ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6411-FAG",
        "equiv_brand": "FAG",
        "level": "partial",
        "note": "Same 55×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6411-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 55×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6411",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 55×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6411-zz",
      "6411zz",
      "6411-ZZ",
      "6411ZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61812-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6812",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 78,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 12.7,
    "static_load_kN": 10.6,
    "fatigue_load_limit_kN": 0.7,
    "limiting_speed_rpm": 8000,
    "max_rpm": 8000,
    "weight_g": 106,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61812 carries bore code 12 = 60 mm. Outside diameter 78 mm and width 10 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 60 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 60 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61812 with C3 for those conditions.",
      "The 618xx thin section at 60 mm bore has only a 9.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6212.",
      "The open 61812-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 60×78×10 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 61812-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Do not quieten a noisy bearing by preloading it: the 61800-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "The open 61812 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 60 mm bore 61812 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 8000 r/min the grease limiting speed for 61812 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61812 at 12.7 kN dynamic (C) and 10.6 kN static (C0), 0.7 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 106 g, 61812 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 60×78×10 mm envelope of 61812 gives a D/d ratio of 1.30 and only 9.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 12.7/10.6 kN load ratings, 0.7 kN fatigue load limit Cu NTN lists the grease limiting speed at 8000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 106 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6812 on the 60×78×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61812 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Standard catalogue stock of 61812 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61812-NTN bearing?",
        "a": "A 61812-NTN deep-groove ball bearing has a 60 mm bore, 78 mm outer diameter and 10 mm width (2.362 × 3.071 × 0.394 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How should 61812-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 60 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 61812-NTN need?",
        "a": "The open 61812-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "What is the NTN order number for an open 61812?",
        "a": "NTN lists the open 61812 under the bare designation 6812; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 60 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6812?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61812-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6812",
      "61812",
      "61812-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61812-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6812LLU",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 78,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 12.7,
    "static_load_kN": 10.6,
    "fatigue_load_limit_kN": 0.7,
    "limiting_speed_rpm": 4400,
    "max_rpm": 4400,
    "weight_g": 106,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61812-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 12 by five gives the 60 mm bore; the 78 mm outside diameter and 10 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 60 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6812LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Interference on a 60 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61812 with C3 clearance and re-check the residual value after mounting.",
      "The 618xx thin section at 60 mm bore has only a 9.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6212.",
      "Contact seals add drag and heat: 61812-2RS-NTN runs slower and cooler-limited than the open 61812; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 61812-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Vibration during standstill brinells the raceways of a 60 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Never mix components between two 61812-2RS-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the contact-sealed version as 6812LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 60 mm bore 61812 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4400 r/min for 61812; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "NTN rates 61812 at 12.7 kN dynamic (C) and 10.6 kN static (C0), 0.7 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 106 g, 61812 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 60×78×10 mm envelope of 61812 gives a D/d ratio of 1.30 and only 9.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 12.7/10.6 kN load ratings, 0.7 kN fatigue load limit Cu NTN lists the grease limiting speed at 4400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 106 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6812LLU on the 60×78×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61812 in a rated drive.",
      "Order the C3 internal-clearance version (61812 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61812 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61812-2RS-NTN bearing?",
        "a": "A 61812-2RS-NTN deep-groove ball bearing has a 60 mm bore, 78 mm outer diameter and 10 mm width (2.362 × 3.071 × 0.394 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What lubrication does 61812-2RS-NTN need?",
        "a": "61812-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61812 with a housing grease fitting instead."
      },
      {
        "q": "How does the 61812 bore code work?",
        "a": "The last two digits of 61812 are bore code 12, giving 12 × 5 = 60 mm bore. The 78 mm outside diameter and 10 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 61812?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6812LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×78×10 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6812LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61812-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61812-llu",
      "6812llu",
      "61812-2RS",
      "61812-2rs",
      "6812LLU",
      "61812-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61812-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6812LLB",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 78,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 12.7,
    "static_load_kN": 10.6,
    "fatigue_load_limit_kN": 0.7,
    "limiting_speed_rpm": 8000,
    "max_rpm": 8000,
    "weight_g": 106,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61812-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 12 by five gives the 60 mm bore; the 78 mm outside diameter and 10 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 60 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6812LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At 60 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61812 against the shaft shoulder while it cools so the ring cannot creep back.",
      "Only 9.0 mm of radial section separates bore and OD on the 618xx series at 60 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6212.",
      "The low-drag lip of 61812-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 61812-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 60 mm bore position before relying on it as sealed-for-life.",
      "A 60 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Never mix components between two 61812-RSR-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues this low-friction non-contact seal as 6812LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 60 mm bore 61812 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 8000 r/min the grease limiting speed for 61812 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61812 at 12.7 kN dynamic (C) and 10.6 kN static (C0), 0.7 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 106 g, 61812 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 60×78×10 mm envelope of 61812 gives a D/d ratio of 1.30 and only 9.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 12.7/10.6 kN load ratings, 0.7 kN fatigue load limit Cu NTN lists the grease limiting speed at 8000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 106 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6812LLB on the 60×78×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61812 in a rated drive.",
      "Standard catalogue stock of 61812 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61812 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61812-RSR-NTN bearing?",
        "a": "A 61812-RSR-NTN deep-groove ball bearing has a 60 mm bore, 78 mm outer diameter and 10 mm width (2.362 × 3.071 × 0.394 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 61812 bore code work?",
        "a": "The last two digits of 61812 are bore code 12, giving 12 × 5 = 60 mm bore. The 78 mm outside diameter and 10 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does the RSR suffix on 61812-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "What is the NTN suffix for a sealed 61812?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6812LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×78×10 mm ISO 15 envelope."
      },
      {
        "q": "Is 6812LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61812-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61812-llb",
      "6812llb",
      "61812-RSR",
      "61812-rsr",
      "6812LLB",
      "61812-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61812-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6812ZZ",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 78,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 12.7,
    "static_load_kN": 10.6,
    "fatigue_load_limit_kN": 0.7,
    "limiting_speed_rpm": 8000,
    "max_rpm": 8000,
    "weight_g": 106,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61812-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 12 by five gives the 60 mm bore; the 78 mm outside diameter and 10 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 60 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6812ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Interference on a 60 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61812 with C3 clearance and re-check the residual value after mounting.",
      "The 618xx thin section at 60 mm bore has only a 9.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6212.",
      "ZZ shields are non-contact: 61812-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61812-2RS for that.",
      "Do not wash 61812-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61800-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "NTN catalogues the shielded version as 6812ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 60 mm bore 61812 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 8000 r/min the grease limiting speed for 61812 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61812 at 12.7 kN dynamic (C) and 10.6 kN static (C0), 0.7 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 106 g, 61812 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 60×78×10 mm envelope of 61812 gives a D/d ratio of 1.30 and only 9.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 12.7/10.6 kN load ratings, 0.7 kN fatigue load limit Cu NTN lists the grease limiting speed at 8000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 106 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6812ZZ on the 60×78×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61812 in a rated drive.",
      "Standard catalogue stock of 61812 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61812-ZZ-NTN bearing?",
        "a": "A 61812-ZZ-NTN deep-groove ball bearing has a 60 mm bore, 78 mm outer diameter and 10 mm width (2.362 × 3.071 × 0.394 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "Are 61812 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61812 uses the same ISO 15 envelope (60×78×10 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 61812-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61812-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61812 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 61812?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6812ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×78×10 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61812 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6812ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61812-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61812-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×78×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61812-zz",
      "6812zz",
      "61812-ZZ",
      "6812ZZ",
      "61812-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61912-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6912",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 85,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 18.2,
    "static_load_kN": 14.3,
    "fatigue_load_limit_kN": 0.96,
    "limiting_speed_rpm": 7600,
    "max_rpm": 7600,
    "weight_g": 193,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61912 carries bore code 12 = 60 mm. Outside diameter 85 mm and width 13 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 60 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 60 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61912 with C3 for those conditions.",
      "The 619xx thin section at 60 mm bore (12.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "The open 61912-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 60×85×13 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 61900-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61912 units.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 85 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61912-NTN.",
      "Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "The open 61912 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 60 mm bore 61912 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7600 r/min the grease limiting speed for 61912 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 18.2 kN dynamic load rating (C) and 14.3 kN static (C0), 0.96 kN fatigue load limit Cu, 61912 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 193 g, 61912 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 60×85×13 mm envelope of 61912 gives a D/d ratio of 1.42 and 12.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 18.2/14.3 kN load ratings, 0.96 kN fatigue load limit Cu NTN lists the grease limiting speed at 7600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 193 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6912 on the 60×85×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61912 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61912 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61912-NTN bearing?",
        "a": "A 61912-NTN deep-groove ball bearing has a 60 mm bore, 85 mm outer diameter and 13 mm width (2.362 × 3.346 × 0.512 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What lubrication does 61912-NTN need?",
        "a": "The open 61912-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "How does the 61912 bore code work?",
        "a": "The last two digits of 61912 are bore code 12, giving 12 × 5 = 60 mm bore. The 85 mm outside diameter and 13 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN order number for an open 61912?",
        "a": "NTN lists the open 61912 under the bare designation 6912; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 60 mm bore envelope."
      },
      {
        "q": "Is 6912 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61912-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6912",
      "61912",
      "61912-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61912-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6912LLU",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 85,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 18.2,
    "static_load_kN": 14.3,
    "fatigue_load_limit_kN": 0.96,
    "limiting_speed_rpm": 4300,
    "max_rpm": 4300,
    "weight_g": 193,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61912 carries bore code 12 = 60 mm. Outside diameter 85 mm and width 13 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 60 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6912LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 60 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61912 with C3 for those conditions.",
      "The 619xx thin section (12.5 mm section height at 60 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "Heat is the enemy of the sealed 61912-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 61912-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 85 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61912-2RS-NTN.",
      "Vibration during standstill brinells the raceways of a 60 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues the contact-sealed version as 6912LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 60 mm bore 61912 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4300 r/min for 61912; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "At 18.2 kN dynamic load rating (C) and 14.3 kN static (C0), 0.96 kN fatigue load limit Cu, 61912 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 193 g, 61912 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 60×85×13 mm envelope of 61912 gives a D/d ratio of 1.42 and 12.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 18.2/14.3 kN load ratings, 0.96 kN fatigue load limit Cu NTN lists the grease limiting speed at 4300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 193 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6912LLU on the 60×85×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61912 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61912-2RS-NTN bearing?",
        "a": "A 61912-2RS-NTN deep-groove ball bearing has a 60 mm bore, 85 mm outer diameter and 13 mm width (2.362 × 3.346 × 0.512 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What does the 2RS suffix on 61912-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "How does the 61900 compare with other series at the same 60 mm bore?",
        "a": "619 is a thin section one step above 618: 85×13 mm with a 12.5 mm radial section at 60 mm bore; a 6212 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "What is the NTN suffix for a sealed 61912?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6912LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×85×13 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61912 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6912LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61912-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61912-llu",
      "6912llu",
      "61912-2RS",
      "61912-2rs",
      "6912LLU",
      "61912-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61912-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6912LLB",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 85,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 18.2,
    "static_load_kN": 14.3,
    "fatigue_load_limit_kN": 0.96,
    "limiting_speed_rpm": 7600,
    "max_rpm": 7600,
    "weight_g": 193,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61912 carries bore code 12 = 60 mm. Outside diameter 85 mm and width 13 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 60 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6912LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Interference on a 60 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61912 with C3 clearance and re-check the residual value after mounting.",
      "The 619xx thin section (12.5 mm section height at 60 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "RSR low-friction seals on 61912-RSR-NTN run faster than contact-seal 61912-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61912-2RS instead.",
      "The non-contact lip of 61912-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 60 mm bore position before relying on it as sealed-for-life.",
      "Never mix components between two 61912-RSR-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "The housing bore for the 85 mm OD should be round within IT7; an oval bore pinches the outer ring of 61912-RSR-NTN and shows up later as two-point loaded raceway wear.",
      "NTN catalogues this low-friction non-contact seal as 6912LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 60 mm bore 61912 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7600 r/min the grease limiting speed for 61912 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 18.2 kN dynamic load rating (C) and 14.3 kN static (C0), 0.96 kN fatigue load limit Cu, 61912 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 193 g, 61912 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 60×85×13 mm envelope of 61912 gives a D/d ratio of 1.42 and 12.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 18.2/14.3 kN load ratings, 0.96 kN fatigue load limit Cu NTN lists the grease limiting speed at 7600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 193 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6912LLB on the 60×85×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61912 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61912-RSR-NTN bearing?",
        "a": "A 61912-RSR-NTN deep-groove ball bearing has a 60 mm bore, 85 mm outer diameter and 13 mm width (2.362 × 3.346 × 0.512 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 61900 compare with other series at the same 60 mm bore?",
        "a": "619 is a thin section one step above 618: 85×13 mm with a 12.5 mm radial section at 60 mm bore; a 6212 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "Are 61912 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61912 uses the same ISO 15 envelope (60×85×13 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61912?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6912LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×85×13 mm ISO 15 envelope."
      },
      {
        "q": "Is 6912LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61912-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61912-llb",
      "6912llb",
      "61912-RSR",
      "61912-rsr",
      "6912LLB",
      "61912-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61912-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6912ZZ",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 85,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 18.2,
    "static_load_kN": 14.3,
    "fatigue_load_limit_kN": 0.96,
    "limiting_speed_rpm": 7600,
    "max_rpm": 7600,
    "weight_g": 193,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61912 carries bore code 12 = 60 mm. Outside diameter 85 mm and width 13 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 60 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6912ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Interference on a 60 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61912 with C3 clearance and re-check the residual value after mounting.",
      "The 619xx thin section at 60 mm bore (12.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "ZZ shields are non-contact: 61912-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61912-2RS for that.",
      "Do not wash 61912-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Never mix components between two 61912-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the shielded version as 6912ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 60 mm bore 61912 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7600 r/min the grease limiting speed for 61912 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 18.2 kN dynamic load rating (C) and 14.3 kN static (C0), 0.96 kN fatigue load limit Cu, 61912 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 193 g, 61912 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 60×85×13 mm envelope of 61912 gives a D/d ratio of 1.42 and 12.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 18.2/14.3 kN load ratings, 0.96 kN fatigue load limit Cu NTN lists the grease limiting speed at 7600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 193 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6912ZZ on the 60×85×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61912 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61912 is listed.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61912-ZZ-NTN bearing?",
        "a": "A 61912-ZZ-NTN deep-groove ball bearing has a 60 mm bore, 85 mm outer diameter and 13 mm width (2.362 × 3.346 × 0.512 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 61912-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 61900 compare with other series at the same 60 mm bore?",
        "a": "619 is a thin section one step above 618: 85×13 mm with a 12.5 mm radial section at 60 mm bore; a 6212 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "What is the NTN suffix for a sealed 61912?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6912ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×85×13 mm ISO 15 envelope."
      },
      {
        "q": "Is 6912ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61912-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61912-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×85×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61912-zz",
      "6912zz",
      "61912-ZZ",
      "6912ZZ",
      "61912-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "16012",
    "brand": "NTN",
    "manufacturer_designation": "16012",
    "series": "16000-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 95,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 22.1,
    "static_load_kN": 17.5,
    "fatigue_load_limit_kN": 1.2,
    "limiting_speed_rpm": 7000,
    "max_rpm": 7000,
    "weight_g": 283,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "16012 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the narrow 160xx section of the ISO 15 general plan, multiplying bore code 12 by five gives the 60 mm bore; the 95 mm outside diameter and 11 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 60 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Interference on a 60 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 16012 with C3 clearance and re-check the residual value after mounting.",
      "Because the 160xx narrow section shares the 95 mm OD of the 6012 at 60 mm bore but is only 11 mm wide, a housing machined for the wider bearing needs a spacer or relocated circlip — never assume width interchangeability.",
      "Storage matters for open bearings: 16012 leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 16000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 16012 units.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 16012-C3. No clearance suffix means normal CN clearance.",
      "Never mix components between two 16012 units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "The open 16012 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 60 mm bore 16012 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7000 r/min the grease limiting speed for 16012 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 22.1 kN dynamic load rating (C) and 17.5 kN static (C0), 1.2 kN fatigue load limit Cu, 16012 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 283 g, 16012 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 60×95×11 mm envelope of 16012 gives a D/d ratio of 1.58 and 17.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 22.1/17.5 kN load ratings, 1.2 kN fatigue load limit Cu NTN lists the grease limiting speed at 7000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 283 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 16012 on the 60×95×11 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 16012 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 16012 bearing?",
        "a": "A 16012 deep-groove ball bearing has a 60 mm bore, 95 mm outer diameter and 11 mm width (2.362 × 3.74 × 0.433 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What lubrication does 16012 need?",
        "a": "The open 16012 is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "How does the 16012 bore code work?",
        "a": "The last two digits of 16012 are bore code 12, giving 12 × 5 = 60 mm bore. The 95 mm outside diameter and 11 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN order number for an open 16012?",
        "a": "NTN lists the open 16012 under the bare designation 16012; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 60 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 16012?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "16012"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6012-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6012",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 95,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 32.5,
    "static_load_kN": 23.2,
    "fatigue_load_limit_kN": 1.73,
    "limiting_speed_rpm": 7000,
    "max_rpm": 7000,
    "weight_g": 414,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6012 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 12 by five gives the 60 mm bore; the 95 mm outside diameter and 18 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 60 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "At 60 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6012 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 60xx extra-light section at 60 mm bore uses a smaller 95 mm OD than a 6212; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "The open 6012-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 60×95×18 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6012-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 95 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6012-NTN.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 18 mm-wide ring of 6012-NTN drags the lip and overheats it.",
      "The open 6012 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 60 mm bore 6012 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7000 r/min the grease limiting speed for 6012 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 32.5 kN dynamic load rating (C) and 23.2 kN static (C0), 1.73 kN fatigue load limit Cu, 6012 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 414 g, 6012 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 60×95×18 mm envelope of 6012 gives a D/d ratio of 1.58 and 17.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 32.5/23.2 kN load ratings, 1.73 kN fatigue load limit Cu NTN lists the grease limiting speed at 7000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 414 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6012 on the 60×95×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6012 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6012 is listed.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6012-NTN bearing?",
        "a": "A 6012-NTN deep-groove ball bearing has a 60 mm bore, 95 mm outer diameter and 18 mm width (2.362 × 3.74 × 0.709 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 6012 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6012 uses the same ISO 15 envelope (60×95×18 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 6012-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6012-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6012 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 6012?",
        "a": "NTN lists the open 6012 under the bare designation 6012; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 60 mm bore envelope."
      },
      {
        "q": "Is 6012 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6012-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6012",
      "6012-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6012-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6012LLU",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 95,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 32.5,
    "static_load_kN": 23.2,
    "fatigue_load_limit_kN": 1.73,
    "limiting_speed_rpm": 4100,
    "max_rpm": 4100,
    "weight_g": 414,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6012 carries bore code 12 = 60 mm. Outside diameter 95 mm and width 18 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 60 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6012LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At 60 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6012 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 60xx extra-light section at 60 mm bore uses a smaller 95 mm OD than a 6212; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "Heat is the enemy of the sealed 6012-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 6012-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Shaft and housing fillets must clear the bearing chamfer so the 18 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Do not quieten a noisy bearing by preloading it: the 6000-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues the contact-sealed version as 6012LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 60 mm bore 6012 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4100 r/min for 6012; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "At 32.5 kN dynamic load rating (C) and 23.2 kN static (C0), 1.73 kN fatigue load limit Cu, 6012 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 414 g, 6012 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 60×95×18 mm envelope of 6012 gives a D/d ratio of 1.58 and 17.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 32.5/23.2 kN load ratings, 1.73 kN fatigue load limit Cu NTN lists the grease limiting speed at 4100 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 414 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6012LLU on the 60×95×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6012 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6012 is listed.",
      "Order the C3 internal-clearance version (6012 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6012-2RS-NTN bearing?",
        "a": "A 6012-2RS-NTN deep-groove ball bearing has a 60 mm bore, 95 mm outer diameter and 18 mm width (2.362 × 3.74 × 0.709 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What lubrication does 6012-2RS-NTN need?",
        "a": "6012-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6012 with a housing grease fitting instead."
      },
      {
        "q": "How does the 6012 bore code work?",
        "a": "The last two digits of 6012 are bore code 12, giving 12 × 5 = 60 mm bore. The 95 mm outside diameter and 18 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6012?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6012LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×95×18 mm ISO 15 envelope."
      },
      {
        "q": "Is 6012LLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6012-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6012-llu",
      "6012llu",
      "6012-2RS",
      "6012-2rs",
      "6012LLU",
      "6012-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6012-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6012LLB",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 95,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 32.5,
    "static_load_kN": 23.2,
    "fatigue_load_limit_kN": 1.73,
    "limiting_speed_rpm": 7000,
    "max_rpm": 7000,
    "weight_g": 414,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6012-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 12 by five gives the 60 mm bore; the 95 mm outside diameter and 18 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 60 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6012LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 60 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6012 with C3 for those conditions.",
      "Choosing the 60xx extra-light section saves radial space at 60 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6212 before committing to the smaller envelope.",
      "The low-drag lip of 6012-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 6012-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 60 mm bore position before relying on it as sealed-for-life.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6000-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Shaft and housing fillets must clear the bearing chamfer so the 18 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues this low-friction non-contact seal as 6012LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 60 mm bore 6012 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7000 r/min the grease limiting speed for 6012 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 32.5 kN dynamic load rating (C) and 23.2 kN static (C0), 1.73 kN fatigue load limit Cu, 6012 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 414 g, 6012 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 60×95×18 mm envelope of 6012 gives a D/d ratio of 1.58 and 17.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 32.5/23.2 kN load ratings, 1.73 kN fatigue load limit Cu NTN lists the grease limiting speed at 7000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 414 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6012LLB on the 60×95×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6012 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6012 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6012-RSR-NTN bearing?",
        "a": "A 6012-RSR-NTN deep-groove ball bearing has a 60 mm bore, 95 mm outer diameter and 18 mm width (2.362 × 3.74 × 0.709 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What internal clearance does 6012-RSR-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6012-RSR-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6012 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6012-RSR-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 60 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 6012?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6012LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×95×18 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6012LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6012-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6012-llb",
      "6012llb",
      "6012-RSR",
      "6012-rsr",
      "6012LLB",
      "6012-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6012-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6012ZZ",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 95,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 32.5,
    "static_load_kN": 23.2,
    "fatigue_load_limit_kN": 1.73,
    "limiting_speed_rpm": 7000,
    "max_rpm": 7000,
    "weight_g": 414,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6012-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 12 by five gives the 60 mm bore; the 95 mm outside diameter and 18 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 60 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6012ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 60 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6012 with C3 for those conditions.",
      "Choosing the 60xx extra-light section saves radial space at 60 mm bore, but the trade-off is rating: if the drive sees shock or frequent start-stop cycles, re-check the L10 life against a 6212 before committing to the smaller envelope.",
      "ZZ shields are non-contact: 6012-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6012-2RS for that.",
      "Do not wash 6012-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 95 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6012-ZZ-NTN.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6012-ZZ-NTN-C3. No clearance suffix means normal CN clearance.",
      "NTN catalogues the shielded version as 6012ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 60 mm bore 6012 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7000 r/min the grease limiting speed for 6012 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 32.5 kN dynamic load rating (C) and 23.2 kN static (C0), 1.73 kN fatigue load limit Cu, 6012 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 414 g, 6012 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 60×95×18 mm envelope of 6012 gives a D/d ratio of 1.58 and 17.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 32.5/23.2 kN load ratings, 1.73 kN fatigue load limit Cu NTN lists the grease limiting speed at 7000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 414 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6012ZZ on the 60×95×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6012 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6012 is listed.",
      "Standard catalogue stock of 6012 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6012-ZZ-NTN bearing?",
        "a": "A 6012-ZZ-NTN deep-groove ball bearing has a 60 mm bore, 95 mm outer diameter and 18 mm width (2.362 × 3.74 × 0.709 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What lubrication does 6012-ZZ-NTN need?",
        "a": "6012-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "How does the 6012 bore code work?",
        "a": "The last two digits of 6012 are bore code 12, giving 12 × 5 = 60 mm bore. The 95 mm outside diameter and 18 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6012?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6012ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×95×18 mm ISO 15 envelope."
      },
      {
        "q": "Is 6012ZZ a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6012-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6012-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×95×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6012-zz",
      "6012zz",
      "6012-ZZ",
      "6012ZZ",
      "6012-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6212-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6212",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 58,
    "static_load_kN": 36,
    "fatigue_load_limit_kN": 2.83,
    "limiting_speed_rpm": 6000,
    "max_rpm": 6000,
    "weight_g": 783,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6212 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 12 by five gives the 60 mm bore; the 110 mm outside diameter and 22 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 60 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 60 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6212 with C3 for those conditions.",
      "At 60 mm bore the 62xx light series is the workhorse section; its 110×22 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "The open 6212-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 60×110×22 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 6200-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6212 units.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6212-NTN-C3. No clearance suffix means normal CN clearance.",
      "Shaft and housing fillets must clear the bearing chamfer so the 22 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "The open 6212 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 60 mm bore 6212 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 6000 r/min the grease limiting speed for 6212 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6212 at 58 kN dynamic (C) and 36 kN static (C0), 2.83 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 783 g, 6212 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 60×110×22 mm envelope of 6212 gives a D/d ratio of 1.83 and 25.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 58/36 kN load ratings, 2.83 kN fatigue load limit Cu NTN lists the grease limiting speed at 6000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 783 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6212 on the 60×110×22 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6212 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6212 is listed.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6212-NTN bearing?",
        "a": "A 6212-NTN deep-groove ball bearing has a 60 mm bore, 110 mm outer diameter and 22 mm width (2.362 × 4.331 × 0.866 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6212 bore code work?",
        "a": "The last two digits of 6212 are bore code 12, giving 12 × 5 = 60 mm bore. The 110 mm outside diameter and 22 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What does no suffix on 6212 mean?",
        "a": "A bare 6212 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "What is the NTN order number for an open 6212?",
        "a": "NTN lists the open 6212 under the bare designation 6212; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 60 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6212?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6212-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "212",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "212-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6212",
      "6212-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6212-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6212LLU",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 58,
    "static_load_kN": 36,
    "fatigue_load_limit_kN": 2.83,
    "limiting_speed_rpm": 3800,
    "max_rpm": 3800,
    "weight_g": 783,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6212 carries bore code 12 = 60 mm. Outside diameter 110 mm and width 22 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 60 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6212LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 60 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6212 with C3 for those conditions.",
      "At 60 mm bore the 62xx light series is the workhorse section; its 110×22 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "Contact seals add drag and heat: 6212-2RS-NTN runs slower and cooler-limited than the open 6212; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 6212-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 110 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6212-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6212LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 60 mm bore 6212 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 3800 r/min for 6212; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "NTN rates 6212 at 58 kN dynamic (C) and 36 kN static (C0), 2.83 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 783 g, 6212 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 60×110×22 mm envelope of 6212 gives a D/d ratio of 1.83 and 25.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 58/36 kN load ratings, 2.83 kN fatigue load limit Cu NTN lists the grease limiting speed at 3800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 783 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6212LLU on the 60×110×22 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6212 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Order the C3 internal-clearance version (6212 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6212-2RS-NTN bearing?",
        "a": "A 6212-2RS-NTN deep-groove ball bearing has a 60 mm bore, 110 mm outer diameter and 22 mm width (2.362 × 4.331 × 0.866 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What does the 2RS suffix on 6212-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "How does the 6200 compare with other series at the same 60 mm bore?",
        "a": "The '2' is the light diameter series: 110×22 mm with a 25.0 mm radial section at 60 mm bore. A 6312 on the same bore is larger and higher-rated; a 6012 is smaller and lower-rated."
      },
      {
        "q": "What is the NTN suffix for a sealed 6212?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6212LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×110×22 mm ISO 15 envelope."
      },
      {
        "q": "Is 6212LLU a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6212-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "212",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "212-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6212-llu",
      "6212llu",
      "6212-2RS",
      "6212-2rs",
      "6212LLU",
      "6212-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6212-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6212LLB",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 58,
    "static_load_kN": 36,
    "fatigue_load_limit_kN": 2.83,
    "limiting_speed_rpm": 4500,
    "max_rpm": 4500,
    "weight_g": 783,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6212-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 12 by five gives the 60 mm bore; the 110 mm outside diameter and 22 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 60 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6212LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Interference on a 60 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6212 with C3 clearance and re-check the residual value after mounting.",
      "At 60 mm bore the 62xx light series is the workhorse section; its 110×22 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "RSR low-friction seals on 6212-RSR-NTN run faster than contact-seal 6212-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6212-2RS instead.",
      "The non-contact lip of 6212-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 60 mm bore position before relying on it as sealed-for-life.",
      "The housing bore for the 110 mm OD should be round within IT7; an oval bore pinches the outer ring of 6212-RSR-NTN and shows up later as two-point loaded raceway wear.",
      "Do not quieten a noisy bearing by preloading it: the 6200-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "NTN catalogues this low-friction non-contact seal as 6212LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 60 mm bore 6212 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4500 r/min for 6212; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "NTN rates 6212 at 58 kN dynamic (C) and 36 kN static (C0), 2.83 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 783 g, 6212 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 60×110×22 mm envelope of 6212 gives a D/d ratio of 1.83 and 25.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 58/36 kN load ratings, 2.83 kN fatigue load limit Cu NTN lists the grease limiting speed at 4500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 783 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6212LLB on the 60×110×22 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6212 in a rated drive.",
      "Standard catalogue stock of 6212 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6212-RSR-NTN bearing?",
        "a": "A 6212-RSR-NTN deep-groove ball bearing has a 60 mm bore, 110 mm outer diameter and 22 mm width (2.362 × 4.331 × 0.866 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6200 compare with other series at the same 60 mm bore?",
        "a": "The '2' is the light diameter series: 110×22 mm with a 25.0 mm radial section at 60 mm bore. A 6312 on the same bore is larger and higher-rated; a 6012 is smaller and lower-rated."
      },
      {
        "q": "Are 6212 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6212 uses the same ISO 15 envelope (60×110×22 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6212?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6212LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×110×22 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6212LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6212-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "212",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "212-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6212-llb",
      "6212llb",
      "6212-RSR",
      "6212-rsr",
      "6212LLB",
      "6212-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6212-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6212ZZ",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 110,
    "B_mm": 22,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 58,
    "static_load_kN": 36,
    "fatigue_load_limit_kN": 2.83,
    "limiting_speed_rpm": 4500,
    "max_rpm": 4500,
    "weight_g": 783,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6212 carries bore code 12 = 60 mm. Outside diameter 110 mm and width 22 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 60 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6212ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Interference on a 60 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6212 with C3 clearance and re-check the residual value after mounting.",
      "The 62xx light series is the default general-purpose section at 60 mm bore; before upgrading to a 6312 for extra capacity, confirm the housing accepts a 110 mm OD and 22 mm width — it is not a drop-in swap.",
      "ZZ shields are non-contact: 6212-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6212-2RS for that.",
      "Shielded 6212-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Shaft and housing fillets must clear the bearing chamfer so the 22 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Never mix components between two 6212-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the shielded version as 6212ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 60 mm bore 6212 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4500 r/min for 6212; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "NTN rates 6212 at 58 kN dynamic (C) and 36 kN static (C0), 2.83 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 783 g, 6212 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 60×110×22 mm envelope of 6212 gives a D/d ratio of 1.83 and 25.0 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 58/36 kN load ratings, 2.83 kN fatigue load limit Cu NTN lists the grease limiting speed at 4500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 783 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6212ZZ on the 60×110×22 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6212 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6212 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6212-ZZ-NTN bearing?",
        "a": "A 6212-ZZ-NTN deep-groove ball bearing has a 60 mm bore, 110 mm outer diameter and 22 mm width (2.362 × 4.331 × 0.866 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What internal clearance does 6212-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6212-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6212 and verify the residual clearance after mounting."
      },
      {
        "q": "How should 6212-ZZ-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 60 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What is the NTN suffix for a sealed 6212?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6212ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×110×22 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6212 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6212ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6212-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6212-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "212",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "212-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×110×22 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6212-zz",
      "6212zz",
      "6212-ZZ",
      "6212ZZ",
      "6212-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6312-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6312",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 90.5,
    "static_load_kN": 52,
    "fatigue_load_limit_kN": 4.1,
    "limiting_speed_rpm": 5400,
    "max_rpm": 5400,
    "weight_g": 1730,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6312 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 12 by five gives the 60 mm bore; the 130 mm outside diameter and 31 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 60 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Interference on a 60 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6312 with C3 clearance and re-check the residual value after mounting.",
      "The 63xx medium series gains rating at 60 mm bore through a 130 mm OD and 31 mm width; the heavier rolling elements also trade away some speed versus a 6212.",
      "The open 6312-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 60×130×31 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Storage matters for open bearings: 6312-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Never mix components between two 6312-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 130 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6312-NTN.",
      "The open 6312 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 60 mm bore 6312 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 5400 r/min the grease limiting speed for 6312 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 90.5 kN dynamic load rating (C) and 52 kN static (C0), 4.1 kN fatigue load limit Cu, 6312 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 1730 g (1.7 kg), 6312 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 60×130×31 mm envelope of 6312 gives a D/d ratio of 2.17 and 35.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 90.5/52 kN load ratings, 4.1 kN fatigue load limit Cu NTN lists the grease limiting speed at 5400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1730 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6312 on the 60×130×31 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6312 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6312 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6312-NTN bearing?",
        "a": "A 6312-NTN deep-groove ball bearing has a 60 mm bore, 130 mm outer diameter and 31 mm width (2.362 × 5.118 × 1.22 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "Are 6312 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6312 uses the same ISO 15 envelope (60×130×31 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What internal clearance does 6312-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6312-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6312 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN order number for an open 6312?",
        "a": "NTN lists the open 6312 under the bare designation 6312; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 60 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6312 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6312 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6312-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "312",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "312-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6312",
      "6312-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6312-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6312LLU",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 90.5,
    "static_load_kN": 52,
    "fatigue_load_limit_kN": 4.1,
    "limiting_speed_rpm": 3600,
    "max_rpm": 3600,
    "weight_g": 1730,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6312-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 12 by five gives the 60 mm bore; the 130 mm outside diameter and 31 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 60 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6312LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Interference on a 60 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6312 with C3 clearance and re-check the residual value after mounting.",
      "The 63xx medium series gains rating at 60 mm bore through a 130 mm OD and 31 mm width; the heavier rolling elements also trade away some speed versus a 6212.",
      "Contact seals add drag and heat: 6312-2RS-NTN runs slower and cooler-limited than the open 6312; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 6312-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 31 mm-wide ring of 6312-2RS-NTN drags the lip and overheats it.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 130 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6312-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6312LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 60 mm bore 6312 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 3600 r/min for 6312; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "At 90.5 kN dynamic load rating (C) and 52 kN static (C0), 4.1 kN fatigue load limit Cu, 6312 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 1730 g (1.7 kg), 6312 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 60×130×31 mm envelope of 6312 gives a D/d ratio of 2.17 and 35.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 90.5/52 kN load ratings, 4.1 kN fatigue load limit Cu NTN lists the grease limiting speed at 3600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1730 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6312LLU on the 60×130×31 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6312 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "Order the C3 internal-clearance version (6312 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6312-2RS-NTN bearing?",
        "a": "A 6312-2RS-NTN deep-groove ball bearing has a 60 mm bore, 130 mm outer diameter and 31 mm width (2.362 × 5.118 × 1.22 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What lubrication does 6312-2RS-NTN need?",
        "a": "6312-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6312 with a housing grease fitting instead."
      },
      {
        "q": "How does the 6312 bore code work?",
        "a": "The last two digits of 6312 are bore code 12, giving 12 × 5 = 60 mm bore. The 130 mm outside diameter and 31 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6312?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6312LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×130×31 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6312 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6312LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6312-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "312",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "312-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6312-llu",
      "6312llu",
      "6312-2RS",
      "6312-2rs",
      "6312LLU",
      "6312-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6312-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6312LLB",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 90.5,
    "static_load_kN": 52,
    "fatigue_load_limit_kN": 4.1,
    "limiting_speed_rpm": 5400,
    "max_rpm": 5400,
    "weight_g": 1730,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6312 carries bore code 12 = 60 mm. Outside diameter 130 mm and width 31 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 60 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6312LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 60 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6312 with C3 for those conditions.",
      "The 63xx medium section at 60 mm bore gains dynamic rating through larger rolling elements on a 130 mm OD; the penalty is mass and a lower limiting speed than the 6212 — do not specify it for speed-critical shafts.",
      "The low-drag lip of 6312-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 6312-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 60 mm bore position before relying on it as sealed-for-life.",
      "Shaft and housing fillets must clear the bearing chamfer so the 31 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Vibration during standstill brinells the raceways of a 60 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues this low-friction non-contact seal as 6312LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 60 mm bore 6312 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 5400 r/min the grease limiting speed for 6312 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 90.5 kN dynamic load rating (C) and 52 kN static (C0), 4.1 kN fatigue load limit Cu, 6312 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 1730 g (1.7 kg), 6312 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 60×130×31 mm envelope of 6312 gives a D/d ratio of 2.17 and 35.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 90.5/52 kN load ratings, 4.1 kN fatigue load limit Cu NTN lists the grease limiting speed at 5400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1730 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6312LLB on the 60×130×31 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6312 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Order the C3 internal-clearance version (6312 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6312-RSR-NTN bearing?",
        "a": "A 6312-RSR-NTN deep-groove ball bearing has a 60 mm bore, 130 mm outer diameter and 31 mm width (2.362 × 5.118 × 1.22 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What lubrication does 6312-RSR-NTN need?",
        "a": "6312-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6312 with a housing grease fitting instead."
      },
      {
        "q": "How does the 6312 bore code work?",
        "a": "The last two digits of 6312 are bore code 12, giving 12 × 5 = 60 mm bore. The 130 mm outside diameter and 31 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6312?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6312LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×130×31 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6312LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6312-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "312",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "312-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6312-llb",
      "6312llb",
      "6312-RSR",
      "6312-rsr",
      "6312LLB",
      "6312-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6312-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6312ZZ",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 130,
    "B_mm": 31,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 90.5,
    "static_load_kN": 52,
    "fatigue_load_limit_kN": 4.1,
    "limiting_speed_rpm": 5400,
    "max_rpm": 5400,
    "weight_g": 1730,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6312 carries bore code 12 = 60 mm. Outside diameter 130 mm and width 31 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 60 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6312ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 60 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6312 with C3 for those conditions.",
      "The 63xx medium section at 60 mm bore gains dynamic rating through larger rolling elements on a 130 mm OD; the penalty is mass and a lower limiting speed than the 6212 — do not specify it for speed-critical shafts.",
      "ZZ shields are non-contact: 6312-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6312-2RS for that.",
      "Shielded 6312-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 31 mm-wide ring of 6312-ZZ-NTN drags the lip and overheats it.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6312-ZZ-NTN-C3. No clearance suffix means normal CN clearance.",
      "NTN catalogues the shielded version as 6312ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 60 mm bore 6312 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 5400 r/min the grease limiting speed for 6312 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 90.5 kN dynamic load rating (C) and 52 kN static (C0), 4.1 kN fatigue load limit Cu, 6312 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 1730 g (1.7 kg), 6312 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 60×130×31 mm envelope of 6312 gives a D/d ratio of 2.17 and 35.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 90.5/52 kN load ratings, 4.1 kN fatigue load limit Cu NTN lists the grease limiting speed at 5400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1730 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6312ZZ on the 60×130×31 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6312 in a rated drive.",
      "Order the C3 internal-clearance version (6312 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6312-ZZ-NTN bearing?",
        "a": "A 6312-ZZ-NTN deep-groove ball bearing has a 60 mm bore, 130 mm outer diameter and 31 mm width (2.362 × 5.118 × 1.22 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What lubrication does 6312-ZZ-NTN need?",
        "a": "6312-ZZ-NTN is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "How does the 6312 bore code work?",
        "a": "The last two digits of 6312 are bore code 12, giving 12 × 5 = 60 mm bore. The 130 mm outside diameter and 31 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6312?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6312ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×130×31 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6312 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6312ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6312-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6312-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "312",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "312-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×130×31 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6312-zz",
      "6312zz",
      "6312-ZZ",
      "6312ZZ",
      "6312-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6412-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6412",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 150,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 113,
    "static_load_kN": 64.5,
    "fatigue_load_limit_kN": 4.9,
    "limiting_speed_rpm": 4800,
    "max_rpm": 4800,
    "weight_g": 2770,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6400-series (diameter series 4 of ISO 15) the last two digits encode the bore: 6412 carries bore code 12 = 60 mm. Outside diameter 150 mm and width 35 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 60 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "At 60 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 6412 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 64xx heavy section at 60 mm bore (150 mm OD) is built for high-load, lower-speed duty; specifying it in a high-rpm motor gives excess heat and short grease life — use 62/63 there.",
      "The open 6412-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 60×150×35 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 6400-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6412 units.",
      "Never mix components between two 6412-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6400-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "The open 6412 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 60 mm bore 6412 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4800 r/min for 6412; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "At 113 kN dynamic load rating (C) and 64.5 kN static (C0), 4.9 kN fatigue load limit Cu, 6412 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 2770 g (2.8 kg), 6412 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 60×150×35 mm envelope of 6412 gives a D/d ratio of 2.50 and 45.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 113/64.5 kN load ratings, 4.9 kN fatigue load limit Cu NTN lists the grease limiting speed at 4800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 2770 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6412 on the 60×150×35 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6412 in a rated drive.",
      "Standard catalogue stock of 6412 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6412 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6412-NTN bearing?",
        "a": "A 6412-NTN deep-groove ball bearing has a 60 mm bore, 150 mm outer diameter and 35 mm width (2.362 × 5.906 × 1.378 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How should 6412-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 60 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6412-NTN need?",
        "a": "The open 6412-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "What is the NTN order number for an open 6412?",
        "a": "NTN lists the open 6412 under the bare designation 6412; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 60 mm bore envelope."
      },
      {
        "q": "Is 6412 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6412-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 60×150×35 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6412",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 60×150×35 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6412",
      "6412-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6412-ZZ",
    "brand": "NTN",
    "manufacturer_designation": "6412ZZ",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 60,
    "D_mm": 150,
    "B_mm": 35,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 113,
    "static_load_kN": 64.5,
    "fatigue_load_limit_kN": 4.9,
    "limiting_speed_rpm": 4800,
    "max_rpm": 4800,
    "weight_g": 2770,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6412-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the heavy 64xx section (diameter series 4 of ISO 15), multiplying bore code 12 by five gives the 60 mm bore; the 150 mm outside diameter and 35 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 60 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6412ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 60 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6412 with C3 for those conditions.",
      "The 64xx heavy section at 60 mm bore exists for high radial load at moderate rpm; its 150 mm OD and 35 mm width demand a larger housing, and grease life at motor speeds is short — treat it as a low-speed, high-load choice.",
      "ZZ shields are non-contact: 6412-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6412-2RS for that.",
      "Shielded 6412-ZZ units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "Shaft and housing fillets must clear the bearing chamfer so the 35 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6400-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "NTN catalogues the shielded version as 6412ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 60 mm bore 6412 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4800 r/min for 6412; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "At 113 kN dynamic load rating (C) and 64.5 kN static (C0), 4.9 kN fatigue load limit Cu, 6412 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 2770 g (2.8 kg), 6412 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 60×150×35 mm envelope of 6412 gives a D/d ratio of 2.50 and 45.0 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 113/64.5 kN load ratings, 4.9 kN fatigue load limit Cu NTN lists the grease limiting speed at 4800 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 2770 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6412ZZ on the 60×150×35 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6412 in a rated drive.",
      "Standard catalogue stock of 6412 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6412-ZZ bearing?",
        "a": "A 6412-ZZ deep-groove ball bearing has a 60 mm bore, 150 mm outer diameter and 35 mm width (2.362 × 5.906 × 1.378 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What lubrication does 6412-ZZ need?",
        "a": "6412-ZZ is greased at the factory and the shields hold the fill for the bearing's service life; relubrication is not intended, and adding grease through the shield gap usually forces dirt in with it."
      },
      {
        "q": "How does the 6412 bore code work?",
        "a": "The last two digits of 6412 are bore code 12, giving 12 × 5 = 60 mm bore. The 150 mm outside diameter and 35 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 6412?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6412ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 60×150×35 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6412ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6412-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 60×150×35 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6412",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 60×150×35 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=6",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6412-zz",
      "6412zz",
      "6412-ZZ",
      "6412ZZ"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61813-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6813",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 85,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 12.8,
    "static_load_kN": 11,
    "fatigue_load_limit_kN": 0.73,
    "limiting_speed_rpm": 7400,
    "max_rpm": 7400,
    "weight_g": 128,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61813 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 13 by five gives the 65 mm bore; the 85 mm outside diameter and 10 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 65 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "lay shafts and idler shafts",
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "At 65 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61813 against the shaft shoulder while it cools so the ring cannot creep back.",
      "Only 10.0 mm of radial section separates bore and OD on the 618xx series at 65 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6213.",
      "The open 61813-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 65×85×10 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 61800-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61813 units.",
      "The housing bore for the 85 mm OD should be round within IT7; an oval bore pinches the outer ring of 61813-NTN and shows up later as two-point loaded raceway wear.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 61813-NTN-C3. No clearance suffix means normal CN clearance.",
      "The open 61813 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 65 mm bore 61813 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7400 r/min the grease limiting speed for 61813 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61813 at 12.8 kN dynamic (C) and 11 kN static (C0), 0.73 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 128 g, 61813 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 65×85×10 mm envelope of 61813 gives a D/d ratio of 1.31 and only 10.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 12.8/11 kN load ratings, 0.73 kN fatigue load limit Cu NTN lists the grease limiting speed at 7400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 128 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6813 on the 65×85×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61813 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61813 is listed.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61813-NTN bearing?",
        "a": "A 61813-NTN deep-groove ball bearing has a 65 mm bore, 85 mm outer diameter and 10 mm width (2.559 × 3.346 × 0.394 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How should 61813-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 65 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 61813-NTN need?",
        "a": "The open 61813-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "What is the NTN order number for an open 61813?",
        "a": "NTN lists the open 61813 under the bare designation 6813; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 65 mm bore envelope."
      },
      {
        "q": "Does NTN offer 61813 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6813 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61813-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6813",
      "61813",
      "61813-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61813-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6813LLU",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 85,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 12.8,
    "static_load_kN": 11,
    "fatigue_load_limit_kN": 0.73,
    "limiting_speed_rpm": 4100,
    "max_rpm": 4100,
    "weight_g": 128,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61813-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 13 by five gives the 65 mm bore; the 85 mm outside diameter and 10 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 65 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6813LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 65 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61813 with C3 for those conditions.",
      "Only 10.0 mm of radial section separates bore and OD on the 618xx series at 65 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6213.",
      "Contact seals add drag and heat: 61813-2RS-NTN runs slower and cooler-limited than the open 61813; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Heat is the enemy of the sealed 61813-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never mix components between two 61813-2RS-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Measure the shaft, do not trust the drawing: a 65 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61813-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6813LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 65 mm bore 61813 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4100 r/min for 61813; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "NTN rates 61813 at 12.8 kN dynamic (C) and 11 kN static (C0), 0.73 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 128 g, 61813 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 65×85×10 mm envelope of 61813 gives a D/d ratio of 1.31 and only 10.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 12.8/11 kN load ratings, 0.73 kN fatigue load limit Cu NTN lists the grease limiting speed at 4100 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 128 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6813LLU on the 65×85×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61813 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61813-2RS-NTN bearing?",
        "a": "A 61813-2RS-NTN deep-groove ball bearing has a 65 mm bore, 85 mm outer diameter and 10 mm width (2.559 × 3.346 × 0.394 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What lubrication does 61813-2RS-NTN need?",
        "a": "61813-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61813 with a housing grease fitting instead."
      },
      {
        "q": "How does the 61813 bore code work?",
        "a": "The last two digits of 61813 are bore code 13, giving 13 × 5 = 65 mm bore. The 85 mm outside diameter and 10 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 61813?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6813LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 65×85×10 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6813LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61813-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61813-llu",
      "6813llu",
      "61813-2RS",
      "61813-2rs",
      "6813LLU",
      "61813-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61813-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6813LLB",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 85,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 12.8,
    "static_load_kN": 11,
    "fatigue_load_limit_kN": 0.73,
    "limiting_speed_rpm": 7400,
    "max_rpm": 7400,
    "weight_g": 128,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61813-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 13 by five gives the 65 mm bore; the 85 mm outside diameter and 10 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 65 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6813LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "false brinelling from vibration while the shaft is stationary",
      "fretting corrosion on a loose shaft seat"
    ],
    "pitfalls": [
      "At 65 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61813 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 618xx thin section at 65 mm bore has only a 10.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6213.",
      "RSR low-friction seals on 61813-RSR-NTN run faster than contact-seal 61813-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 61813-2RS instead.",
      "The low-drag lip of 61813-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "Shaft and housing fillets must clear the bearing chamfer so the 10 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "The housing bore for the 85 mm OD should be round within IT7; an oval bore pinches the outer ring of 61813-RSR-NTN and shows up later as two-point loaded raceway wear.",
      "NTN catalogues this low-friction non-contact seal as 6813LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 65 mm bore 61813 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7400 r/min the grease limiting speed for 61813 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61813 at 12.8 kN dynamic (C) and 11 kN static (C0), 0.73 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 128 g, 61813 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 65×85×10 mm envelope of 61813 gives a D/d ratio of 1.31 and only 10.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 12.8/11 kN load ratings, 0.73 kN fatigue load limit Cu NTN lists the grease limiting speed at 7400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 128 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6813LLB on the 65×85×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61813 in a rated drive.",
      "Order the C3 internal-clearance version (61813 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61813-RSR-NTN bearing?",
        "a": "A 61813-RSR-NTN deep-groove ball bearing has a 65 mm bore, 85 mm outer diameter and 10 mm width (2.559 × 3.346 × 0.394 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 61800 compare with other series at the same 65 mm bore?",
        "a": "618 is an extra-thin section: 85×10 mm, only 10.0 mm radial section at 65 mm bore, far smaller than a 6213, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "Are 61813 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61813 uses the same ISO 15 envelope (65×85×10 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61813?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6813LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 65×85×10 mm ISO 15 envelope."
      },
      {
        "q": "Is 6813LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61813-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61813-llb",
      "6813llb",
      "61813-RSR",
      "61813-rsr",
      "6813LLB",
      "61813-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61813-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6813ZZ",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 85,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 12.8,
    "static_load_kN": 11,
    "fatigue_load_limit_kN": 0.73,
    "limiting_speed_rpm": 7400,
    "max_rpm": 7400,
    "weight_g": 128,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61813-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the extra-thin 618xx section (diameter series 8 of ISO 15), multiplying bore code 13 by five gives the 65 mm bore; the 85 mm outside diameter and 10 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 65 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6813ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "textile machinery",
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 65 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61813 with C3 for those conditions.",
      "Only 10.0 mm of radial section separates bore and OD on the 618xx series at 65 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6213.",
      "ZZ shields are non-contact: 61813-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 61813-2RS for that.",
      "Do not wash 61813-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Do not quieten a noisy bearing by preloading it: the 61800-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.",
      "Never mix components between two 61813-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the shielded version as 6813ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 65 mm bore 61813 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7400 r/min the grease limiting speed for 61813 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61813 at 12.8 kN dynamic (C) and 11 kN static (C0), 0.73 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 128 g, 61813 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 65×85×10 mm envelope of 61813 gives a D/d ratio of 1.31 and only 10.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 12.8/11 kN load ratings, 0.73 kN fatigue load limit Cu NTN lists the grease limiting speed at 7400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 128 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6813ZZ on the 65×85×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61813 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61813-ZZ-NTN bearing?",
        "a": "A 61813-ZZ-NTN deep-groove ball bearing has a 65 mm bore, 85 mm outer diameter and 10 mm width (2.559 × 3.346 × 0.394 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "How does the 61800 compare with other series at the same 65 mm bore?",
        "a": "618 is an extra-thin section: 85×10 mm, only 10.0 mm radial section at 65 mm bore, far smaller than a 6213, for space-limited layouts at the cost of load rating and misalignment tolerance."
      },
      {
        "q": "Are 61813 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61813 uses the same ISO 15 envelope (65×85×10 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 61813?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6813ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 65×85×10 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61813 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6813ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61813-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61813-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×85×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61813-zz",
      "6813zz",
      "61813-ZZ",
      "6813ZZ",
      "61813-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61913-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6913",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 90,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 19.3,
    "static_load_kN": 16.1,
    "fatigue_load_limit_kN": 1.07,
    "limiting_speed_rpm": 7000,
    "max_rpm": 7000,
    "weight_g": 206,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61913 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 13 by five gives the 65 mm bore; the 90 mm outside diameter and 13 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 65 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 65 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61913 with C3 for those conditions.",
      "The 619xx thin section at 65 mm bore (12.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "The open 61913-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 65×90×13 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 61900-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61913 units.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "The housing bore for the 90 mm OD should be round within IT7; an oval bore pinches the outer ring of 61913-NTN and shows up later as two-point loaded raceway wear.",
      "The open 61913 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 65 mm bore 61913 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7000 r/min the grease limiting speed for 61913 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 19.3 kN dynamic load rating (C) and 16.1 kN static (C0), 1.07 kN fatigue load limit Cu, 61913 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 206 g, 61913 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 65×90×13 mm envelope of 61913 gives a D/d ratio of 1.38 and only 12.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 19.3/16.1 kN load ratings, 1.07 kN fatigue load limit Cu NTN lists the grease limiting speed at 7000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 206 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6913 on the 65×90×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61913 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Standard catalogue stock of 61913 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61913-NTN bearing?",
        "a": "A 61913-NTN deep-groove ball bearing has a 65 mm bore, 90 mm outer diameter and 13 mm width (2.559 × 3.543 × 0.512 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How should 61913-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 65 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 61913-NTN need?",
        "a": "The open 61913-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "What is the NTN order number for an open 61913?",
        "a": "NTN lists the open 61913 under the bare designation 6913; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 65 mm bore envelope."
      },
      {
        "q": "What cage does NTN fit in 6913?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61913-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6913",
      "61913",
      "61913-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61913-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6913LLU",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 90,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 19.3,
    "static_load_kN": 16.1,
    "fatigue_load_limit_kN": 1.07,
    "limiting_speed_rpm": 4000,
    "max_rpm": 4000,
    "weight_g": 206,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61913 carries bore code 13 = 65 mm. Outside diameter 90 mm and width 13 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 65 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6913LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "packaging machinery",
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 65 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 61913 with C3 for those conditions.",
      "The 619xx thin section at 65 mm bore (12.5 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.",
      "Contact seals add drag and heat: 61913-2RS-NTN runs slower and cooler-limited than the open 61913; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 61913-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Vibration during standstill brinells the raceways of a 65 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "A 65 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues the contact-sealed version as 6913LLU (suffix LU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 65 mm bore 61913 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4000 r/min for 61913; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "At 19.3 kN dynamic load rating (C) and 16.1 kN static (C0), 1.07 kN fatigue load limit Cu, 61913 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 206 g, 61913 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 65×90×13 mm envelope of 61913 gives a D/d ratio of 1.38 and only 12.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 19.3/16.1 kN load ratings, 1.07 kN fatigue load limit Cu NTN lists the grease limiting speed at 4000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 206 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6913LLU on the 65×90×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61913 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61913 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61913-2RS-NTN bearing?",
        "a": "A 61913-2RS-NTN deep-groove ball bearing has a 65 mm bore, 90 mm outer diameter and 13 mm width (2.559 × 3.543 × 0.512 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What lubrication does 61913-2RS-NTN need?",
        "a": "61913-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 61913 with a housing grease fitting instead."
      },
      {
        "q": "How does the 61913 bore code work?",
        "a": "The last two digits of 61913 are bore code 13, giving 13 × 5 = 65 mm bore. The 90 mm outside diameter and 13 mm width follow the ISO 15 diameter series, not the bore code alone."
      },
      {
        "q": "What is the NTN suffix for a sealed 61913?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6913LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 65×90×13 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6913LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61913-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61913-llu",
      "6913llu",
      "61913-2RS",
      "61913-2rs",
      "6913LLU",
      "61913-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61913-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6913LLB",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 90,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 19.3,
    "static_load_kN": 16.1,
    "fatigue_load_limit_kN": 1.07,
    "limiting_speed_rpm": 7000,
    "max_rpm": 7000,
    "weight_g": 206,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61913 carries bore code 13 = 65 mm. Outside diameter 90 mm and width 13 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 65 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6913LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Interference on a 65 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61913 with C3 clearance and re-check the residual value after mounting.",
      "The 619xx thin section (12.5 mm section height at 65 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "The low-drag lip of 61913-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 61913-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 65 mm bore position before relying on it as sealed-for-life.",
      "Shaft and housing fillets must clear the bearing chamfer so the 13 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "A 65 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "NTN catalogues this low-friction non-contact seal as 6913LLB (suffix LB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 65 mm bore 61913 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7000 r/min the grease limiting speed for 61913 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 19.3 kN dynamic load rating (C) and 16.1 kN static (C0), 1.07 kN fatigue load limit Cu, 61913 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 206 g, 61913 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 65×90×13 mm envelope of 61913 gives a D/d ratio of 1.38 and only 12.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 19.3/16.1 kN load ratings, 1.07 kN fatigue load limit Cu NTN lists the grease limiting speed at 7000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 206 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6913LLB on the 65×90×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61913 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61913-RSR-NTN bearing?",
        "a": "A 61913-RSR-NTN deep-groove ball bearing has a 65 mm bore, 90 mm outer diameter and 13 mm width (2.559 × 3.543 × 0.512 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "Are 61913 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 61913 uses the same ISO 15 envelope (65×90×13 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 61913-RSR-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 61913-RSR-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 61913 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 61913?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6913LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 65×90×13 mm ISO 15 envelope."
      },
      {
        "q": "Is 6913LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61913-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-RSR",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61913-llb",
      "6913llb",
      "61913-RSR",
      "61913-rsr",
      "6913LLB",
      "61913-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61913-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6913ZZ",
    "series": "61900-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 90,
    "B_mm": 13,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 19.3,
    "static_load_kN": 16.1,
    "fatigue_load_limit_kN": 1.07,
    "limiting_speed_rpm": 7000,
    "max_rpm": 7000,
    "weight_g": 206,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "61913-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the thin 619xx section (diameter series 9 of ISO 15), multiplying bore code 13 by five gives the 65 mm bore; the 90 mm outside diameter and 13 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 65 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6913ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts",
      "textile machinery"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Interference on a 65 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 61913 with C3 clearance and re-check the residual value after mounting.",
      "The 619xx thin section (12.5 mm section height at 65 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.",
      "Do not wash 61913-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Shielded 61913-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.",
      "A 65 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues the shielded version as 6913ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 65 mm bore 61913 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 7000 r/min the grease limiting speed for 61913 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 19.3 kN dynamic load rating (C) and 16.1 kN static (C0), 1.07 kN fatigue load limit Cu, 61913 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 206 g, 61913 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 65×90×13 mm envelope of 61913 gives a D/d ratio of 1.38 and only 12.5 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 19.3/16.1 kN load ratings, 1.07 kN fatigue load limit Cu NTN lists the grease limiting speed at 7000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 206 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6913ZZ on the 65×90×13 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61913 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 61913 is listed.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61913-ZZ-NTN bearing?",
        "a": "A 61913-ZZ-NTN deep-groove ball bearing has a 65 mm bore, 90 mm outer diameter and 13 mm width (2.559 × 3.543 × 0.512 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 61913-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 61900 compare with other series at the same 65 mm bore?",
        "a": "619 is a thin section one step above 618: 90×13 mm with a 12.5 mm radial section at 65 mm bore; a 6213 on the same bore is substantially larger and more heavily rated."
      },
      {
        "q": "What is the NTN suffix for a sealed 61913?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6913ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 65×90×13 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 61913 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6913ZZ is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61913-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-ZZ",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61913-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×90×13 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "61913-zz",
      "6913zz",
      "61913-ZZ",
      "6913ZZ",
      "61913-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "16013",
    "brand": "NTN",
    "manufacturer_designation": "16013",
    "series": "16000-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 100,
    "B_mm": 11,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 22.7,
    "static_load_kN": 18.7,
    "fatigue_load_limit_kN": 1.26,
    "limiting_speed_rpm": 6500,
    "max_rpm": 6500,
    "weight_g": 307,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 16000-series (the narrow extra-light section of ISO 15) the last two digits encode the bore: 16013 carries bore code 13 = 65 mm. Outside diameter 100 mm and width 11 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 65 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "At 65 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 16013 against the shaft shoulder while it cools so the ring cannot creep back.",
      "Because the 160xx narrow section shares the 100 mm OD of the 6013 at 65 mm bore but is only 11 mm wide, a housing machined for the wider bearing needs a spacer or relocated circlip — never assume width interchangeability.",
      "The open 16013 has no lubricant retention: grease escapes and contaminants migrate straight into the 65×100×11 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 16000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 16013 units.",
      "Measure the shaft, do not trust the drawing: a 65 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 16013.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 11 mm-wide ring of 16013 drags the lip and overheats it.",
      "The open 16013 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 65 mm bore 16013 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 6500 r/min the grease limiting speed for 16013 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 22.7 kN dynamic load rating (C) and 18.7 kN static (C0), 1.26 kN fatigue load limit Cu, 16013 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 307 g, 16013 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 65×100×11 mm envelope of 16013 gives a D/d ratio of 1.54 and 17.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 22.7/18.7 kN load ratings, 1.26 kN fatigue load limit Cu NTN lists the grease limiting speed at 6500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 307 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 16013 on the 65×100×11 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 16013 in a rated drive.",
      "Standard catalogue stock of 16013 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 16013 bearing?",
        "a": "A 16013 deep-groove ball bearing has a 65 mm bore, 100 mm outer diameter and 11 mm width (2.559 × 3.937 × 0.433 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 16000 compare with other series at the same 65 mm bore?",
        "a": "160 is the narrow extra-light section: 100×11 mm with a 17.5 mm radial section at 65 mm bore. It has the same bore and outside diameter as the 6013 but a narrower ring, so the two are not width-interchangeable; it appears in the manufacturer catalogues used on this site."
      },
      {
        "q": "Are 16013 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 16013 uses the same ISO 15 envelope (65×100×11 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 16013?",
        "a": "NTN lists the open 16013 under the bare designation 16013; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 65 mm bore envelope."
      },
      {
        "q": "Does NTN offer 16013 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 16013 is the correct choice."
      }
    ],
    "cross_ref": [],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "16013"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6013-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6013",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 100,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 34,
    "static_load_kN": 25.2,
    "fatigue_load_limit_kN": 1.83,
    "limiting_speed_rpm": 6500,
    "max_rpm": 6500,
    "weight_g": 421,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6013 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 13 by five gives the 65 mm bore; the 100 mm outside diameter and 18 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 65 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "conveyor drives",
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Interference on a 65 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6013 with C3 clearance and re-check the residual value after mounting.",
      "The 60xx extra-light section at 65 mm bore uses a smaller 100 mm OD than a 6213; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "Storage matters for open bearings: 6013-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 6000-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6013 units.",
      "Vibration during standstill brinells the raceways of a 65 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 100 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6013-NTN.",
      "The open 6013 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 65 mm bore 6013 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 6500 r/min the grease limiting speed for 6013 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 34 kN dynamic load rating (C) and 25.2 kN static (C0), 1.83 kN fatigue load limit Cu, 6013 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 421 g, 6013 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 65×100×18 mm envelope of 6013 gives a D/d ratio of 1.54 and 17.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 34/25.2 kN load ratings, 1.83 kN fatigue load limit Cu NTN lists the grease limiting speed at 6500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 421 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6013 on the 65×100×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6013 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6013 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6013-NTN bearing?",
        "a": "A 6013-NTN deep-groove ball bearing has a 65 mm bore, 100 mm outer diameter and 18 mm width (2.559 × 3.937 × 0.709 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What does no suffix on 6013 mean?",
        "a": "A bare 6013 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "How does the 6000 compare with other series at the same 65 mm bore?",
        "a": "The second digit is the diameter series: 60 is the smallest standard section (100×18 mm, 17.5 mm radial section) at 65 mm bore — below 62/63/64 in load capacity, for light loads in compact spaces."
      },
      {
        "q": "What is the NTN order number for an open 6013?",
        "a": "NTN lists the open 6013 under the bare designation 6013; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 65 mm bore envelope."
      },
      {
        "q": "Is 6013 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6013-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6013",
      "6013-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6013-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6013LLU",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 100,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 34,
    "static_load_kN": 25.2,
    "fatigue_load_limit_kN": 1.83,
    "limiting_speed_rpm": 3900,
    "max_rpm": 3900,
    "weight_g": 421,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6013-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 13 by five gives the 65 mm bore; the 100 mm outside diameter and 18 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 65 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6013LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "raceway smearing under marginal lubrication at start-up",
      "edge loading from shaft deflection or housing misalignment"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 65 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6013 with C3 for those conditions.",
      "The 60xx extra-light section at 65 mm bore uses a smaller 100 mm OD than a 6213; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "Contact seals add drag and heat: 6013-2RS-NTN runs slower and cooler-limited than the open 6013; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 6013-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Measure the shaft, do not trust the drawing: a 65 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6013-2RS-NTN.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 100 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6013-2RS-NTN.",
      "NTN catalogues the contact-sealed version as 6013LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 65 mm bore 6013 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 3900 r/min for 6013; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "At 34 kN dynamic load rating (C) and 25.2 kN static (C0), 1.83 kN fatigue load limit Cu, 6013 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 421 g, 6013 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 65×100×18 mm envelope of 6013 gives a D/d ratio of 1.54 and 17.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 34/25.2 kN load ratings, 1.83 kN fatigue load limit Cu NTN lists the grease limiting speed at 3900 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 421 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6013LLU on the 65×100×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6013 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6013 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6013-2RS-NTN bearing?",
        "a": "A 6013-2RS-NTN deep-groove ball bearing has a 65 mm bore, 100 mm outer diameter and 18 mm width (2.559 × 3.937 × 0.709 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "What does the 2RS suffix on 6013-2RS mean?",
        "a": "2RS means two contact elastomer seals, one each side, usually over a lifetime grease fill. Sealing against dust and moisture is better than ZZ shields, but the lip drag lowers the speed and temperature ceiling."
      },
      {
        "q": "How does the 6000 compare with other series at the same 65 mm bore?",
        "a": "The second digit is the diameter series: 60 is the smallest standard section (100×18 mm, 17.5 mm radial section) at 65 mm bore — below 62/63/64 in load capacity, for light loads in compact spaces."
      },
      {
        "q": "What is the NTN suffix for a sealed 6013?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6013LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 65×100×18 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6013 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6013LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6013-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6013-llu",
      "6013llu",
      "6013-2RS",
      "6013-2rs",
      "6013LLU",
      "6013-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6013-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6013LLB",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 100,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 34,
    "static_load_kN": 25.2,
    "fatigue_load_limit_kN": 1.83,
    "limiting_speed_rpm": 6500,
    "max_rpm": 6500,
    "weight_g": 421,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6013-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the extra-light 60xx section (diameter series 0 of ISO 15), multiplying bore code 13 by five gives the 65 mm bore; the 100 mm outside diameter and 18 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 65 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6013LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "conveyor drives",
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Interference on a 65 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6013 with C3 clearance and re-check the residual value after mounting.",
      "The 60xx extra-light section at 65 mm bore uses a smaller 100 mm OD than a 6213; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "The low-drag lip of 6013-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 6013-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 65 mm bore position before relying on it as sealed-for-life.",
      "Measure the shaft, do not trust the drawing: a 65 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6013-RSR-NTN.",
      "Vibration during standstill brinells the raceways of a 65 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues this low-friction non-contact seal as 6013LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 65 mm bore 6013 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 6500 r/min the grease limiting speed for 6013 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 34 kN dynamic load rating (C) and 25.2 kN static (C0), 1.83 kN fatigue load limit Cu, 6013 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 421 g, 6013 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 65×100×18 mm envelope of 6013 gives a D/d ratio of 1.54 and 17.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 34/25.2 kN load ratings, 1.83 kN fatigue load limit Cu NTN lists the grease limiting speed at 6500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 421 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6013LLB on the 65×100×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6013 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6013-RSR-NTN bearing?",
        "a": "A 6013-RSR-NTN deep-groove ball bearing has a 65 mm bore, 100 mm outer diameter and 18 mm width (2.559 × 3.937 × 0.709 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How should 6013-RSR-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 65 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6013-RSR-NTN need?",
        "a": "6013-RSR-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6013 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 6013?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6013LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 65×100×18 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6013 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6013LLB is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6013-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6013-llb",
      "6013llb",
      "6013-RSR",
      "6013-rsr",
      "6013LLB",
      "6013-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6013-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6013ZZ",
    "series": "6000-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 100,
    "B_mm": 18,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 34,
    "static_load_kN": 25.2,
    "fatigue_load_limit_kN": 1.83,
    "limiting_speed_rpm": 6500,
    "max_rpm": 6500,
    "weight_g": 421,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6000-series (diameter series 0 of ISO 15) the last two digits encode the bore: 6013 carries bore code 13 = 65 mm. Outside diameter 100 mm and width 18 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 65 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6013ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment",
      "industrial fans"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Interference on a 65 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6013 with C3 clearance and re-check the residual value after mounting.",
      "The 60xx extra-light section at 65 mm bore uses a smaller 100 mm OD than a 6213; load ratings are lower, so do not replace a failed 62-series bearing with a 60-series without re-rating the load.",
      "ZZ shields are non-contact: 6013-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6013-2RS for that.",
      "Do not wash 6013-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6013-ZZ-NTN-C3. No clearance suffix means normal CN clearance.",
      "Never mix components between two 6013-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "NTN catalogues the shielded version as 6013ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 65 mm bore 6013 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 6500 r/min the grease limiting speed for 6013 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "At 34 kN dynamic load rating (C) and 25.2 kN static (C0), 1.83 kN fatigue load limit Cu, 6013 is a medium-load bearing suitable for most electric-motor and pump duty; the C0/C0r ratio matters for preloaded or thrust-loaded arrangements, so confirm the static safety factor with the NTN catalogue.",
      "At 421 g, 6013 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 65×100×18 mm envelope of 6013 gives a D/d ratio of 1.54 and 17.5 mm radial section height — this thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.",
      "The 34/25.2 kN load ratings, 1.83 kN fatigue load limit Cu NTN lists the grease limiting speed at 6500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 421 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6013ZZ on the 65×100×18 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6013 in a rated drive.",
      "Order the C3 internal-clearance version (6013 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6013 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6013-ZZ-NTN bearing?",
        "a": "A 6013-ZZ-NTN deep-groove ball bearing has a 65 mm bore, 100 mm outer diameter and 18 mm width (2.559 × 3.937 × 0.709 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "Are 6013 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6013 uses the same ISO 15 envelope (65×100×18 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 6013-ZZ-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6013-ZZ-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6013 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 6013?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6013ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 65×100×18 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6013ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6013-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6013-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×100×18 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6013-zz",
      "6013zz",
      "6013-ZZ",
      "6013ZZ",
      "6013-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6213-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6213",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 63.5,
    "static_load_kN": 40,
    "fatigue_load_limit_kN": 3.15,
    "limiting_speed_rpm": 5500,
    "max_rpm": 5500,
    "weight_g": 990,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6213 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 13 by five gives the 65 mm bore; the 120 mm outside diameter and 23 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 65 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "conveyor drives",
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Interference on a 65 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6213 with C3 clearance and re-check the residual value after mounting.",
      "The 62xx light series is the default general-purpose section at 65 mm bore; before upgrading to a 6313 for extra capacity, confirm the housing accepts a 120 mm OD and 23 mm width — it is not a drop-in swap.",
      "The open 6213-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 65×120×23 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 6200-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6213 units.",
      "A 65 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Suffixes stack in a defined order — clearance follows the seal code, e.g. 6213-NTN-C3. No clearance suffix means normal CN clearance.",
      "The open 6213 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 65 mm bore 6213 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 5500 r/min the grease limiting speed for 6213 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6213 at 63.5 kN dynamic (C) and 40 kN static (C0), 3.15 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 990 g, 6213 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 65×120×23 mm envelope of 6213 gives a D/d ratio of 1.85 and 27.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 63.5/40 kN load ratings, 3.15 kN fatigue load limit Cu NTN lists the grease limiting speed at 5500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 990 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6213 on the 65×120×23 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6213 in a rated drive.",
      "Order the C3 internal-clearance version (6213 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Standard catalogue stock of 6213 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6213-NTN bearing?",
        "a": "A 6213-NTN deep-groove ball bearing has a 65 mm bore, 120 mm outer diameter and 23 mm width (2.559 × 4.724 × 0.906 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How does the 6200 compare with other series at the same 65 mm bore?",
        "a": "The '2' is the light diameter series: 120×23 mm with a 27.5 mm radial section at 65 mm bore. A 6313 on the same bore is larger and higher-rated; a 6013 is smaller and lower-rated."
      },
      {
        "q": "Are 6213 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6213 uses the same ISO 15 envelope (65×120×23 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting."
      },
      {
        "q": "What is the NTN order number for an open 6213?",
        "a": "NTN lists the open 6213 under the bare designation 6213; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 65 mm bore envelope."
      },
      {
        "q": "Is 6213 a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6213-2RS",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "213",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "213-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6213",
      "6213-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6213-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6213LLU",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 63.5,
    "static_load_kN": 40,
    "fatigue_load_limit_kN": 3.15,
    "limiting_speed_rpm": 3600,
    "max_rpm": 3600,
    "weight_g": 990,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6213-2RS is closed by two contacting elastomer lips over a lifetime grease fill; the lips add friction, so the speed ceiling sits below the open execution. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 13 by five gives the 65 mm bore; the 120 mm outside diameter and 23 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 65 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's contact-seal catalogue number is 6213LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "conveyor drives",
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "electrical pitting in VFD-driven motors without grounding protection",
      "raceway smearing under marginal lubrication at start-up"
    ],
    "pitfalls": [
      "Interference on a 65 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6213 with C3 clearance and re-check the residual value after mounting.",
      "At 65 mm bore the 62xx light series is the workhorse section; its 120×23 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "Contact seals add drag and heat: 6213-2RS-NTN runs slower and cooler-limited than the open 6213; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.",
      "Never wash a sealed 6213-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Vibration during standstill brinells the raceways of a 65 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 23 mm-wide ring of 6213-2RS-NTN drags the lip and overheats it.",
      "NTN catalogues the contact-sealed version as 6213LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 65 mm bore 6213 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 3600 r/min for 6213; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "NTN rates 6213 at 63.5 kN dynamic (C) and 40 kN static (C0), 3.15 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 990 g, 6213 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 65×120×23 mm envelope of 6213 gives a D/d ratio of 1.85 and 27.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 63.5/40 kN load ratings, 3.15 kN fatigue load limit Cu NTN lists the grease limiting speed at 3600 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 990 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6213LLU on the 65×120×23 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6213 in a rated drive.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6213 is listed.",
      "Order the C3 internal-clearance version (6213 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6213-2RS-NTN bearing?",
        "a": "A 6213-2RS-NTN deep-groove ball bearing has a 65 mm bore, 120 mm outer diameter and 23 mm width (2.559 × 4.724 × 0.906 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "How should 6213-2RS-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 65 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6213-2RS-NTN need?",
        "a": "6213-2RS-NTN is supplied pre-greased for life and is not designed to be opened for relubrication; where a relubrication path is required, specify the open 6213 with a housing grease fitting instead."
      },
      {
        "q": "What is the NTN suffix for a sealed 6213?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6213LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 65×120×23 mm ISO 15 envelope."
      },
      {
        "q": "Does NTN offer 6213 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6213LLU is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6213-2RS",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "213",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "213-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6213-llu",
      "6213llu",
      "6213-2RS",
      "6213-2rs",
      "6213LLU",
      "6213-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6213-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6213LLB",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 63.5,
    "static_load_kN": 40,
    "fatigue_load_limit_kN": 3.15,
    "limiting_speed_rpm": 5500,
    "max_rpm": 5500,
    "weight_g": 990,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6213-RSR uses two non-contact elastomer lips with very low drag; coarse debris stays out, but the bearing is not liquid-tight. Within the light 62xx section (diameter series 2 of ISO 15), multiplying bore code 13 by five gives the 65 mm bore; the 120 mm outside diameter and 23 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 65 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6213LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded",
      "brinelling from static overload or hammering during mounting"
    ],
    "pitfalls": [
      "Interference on a 65 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6213 with C3 clearance and re-check the residual value after mounting.",
      "The 62xx light series is the default general-purpose section at 65 mm bore; before upgrading to a 6313 for extra capacity, confirm the housing accepts a 120 mm OD and 23 mm width — it is not a drop-in swap.",
      "RSR low-friction seals on 6213-RSR-NTN run faster than contact-seal 6213-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6213-2RS instead.",
      "The low-drag lip of 6213-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "A 65 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.",
      "Shaft and housing fillets must clear the bearing chamfer so the 23 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "NTN catalogues this low-friction non-contact seal as 6213LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 65 mm bore 6213 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 5500 r/min the grease limiting speed for 6213 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6213 at 63.5 kN dynamic (C) and 40 kN static (C0), 3.15 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 990 g, 6213 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 65×120×23 mm envelope of 6213 gives a D/d ratio of 1.85 and 27.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 63.5/40 kN load ratings, 3.15 kN fatigue load limit Cu NTN lists the grease limiting speed at 5500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 990 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6213LLB on the 65×120×23 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6213 in a rated drive.",
      "Standard catalogue stock of 6213 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6213-RSR-NTN bearing?",
        "a": "A 6213-RSR-NTN deep-groove ball bearing has a 65 mm bore, 120 mm outer diameter and 23 mm width (2.559 × 4.724 × 0.906 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "What does the RSR suffix on 6213-RSR mean?",
        "a": "RSR means two low-friction non-contact rubber seals. They keep coarse debris out with minimal drag (speed close to the open bearing) but are not liquid-tight; use -2RS contact seals for wet or fine-dust environments."
      },
      {
        "q": "How does the 6200 compare with other series at the same 65 mm bore?",
        "a": "The '2' is the light diameter series: 120×23 mm with a 27.5 mm radial section at 65 mm bore. A 6313 on the same bore is larger and higher-rated; a 6013 is smaller and lower-rated."
      },
      {
        "q": "What is the NTN suffix for a sealed 6213?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6213LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 65×120×23 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6213LLB?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6213-2RS",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "213",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "213-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6213-llb",
      "6213llb",
      "6213-RSR",
      "6213-rsr",
      "6213LLB",
      "6213-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6213-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6213ZZ",
    "series": "6200-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 120,
    "B_mm": 23,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 63.5,
    "static_load_kN": 40,
    "fatigue_load_limit_kN": 3.15,
    "limiting_speed_rpm": 5500,
    "max_rpm": 5500,
    "weight_g": 990,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6213 carries bore code 13 = 65 mm. Outside diameter 120 mm and width 23 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 65 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN catalogue order number: 6213ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "material-handling equipment",
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 65 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6213 with C3 for those conditions.",
      "At 65 mm bore the 62xx light series is the workhorse section; its 120×23 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.",
      "ZZ shields are non-contact: 6213-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6213-2RS for that.",
      "Do not wash 6213-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "The housing bore for the 120 mm OD should be round within IT7; an oval bore pinches the outer ring of 6213-ZZ-NTN and shows up later as two-point loaded raceway wear.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues the shielded version as 6213ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 65 mm bore 6213 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 5500 r/min the grease limiting speed for 6213 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 6213 at 63.5 kN dynamic (C) and 40 kN static (C0), 3.15 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.",
      "At 990 g, 6213 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.",
      "The 65×120×23 mm envelope of 6213 gives a D/d ratio of 1.85 and 27.5 mm radial section height — a standard medium section that balances load capacity and speed; for this geometry the pressed-steel cage is adequate up to the listed limiting speed, and C3 clearance is the common choice for hot shafts.",
      "The 63.5/40 kN load ratings, 3.15 kN fatigue load limit Cu NTN lists the grease limiting speed at 5500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 990 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6213ZZ on the 65×120×23 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6213 in a rated drive.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6213-ZZ-NTN bearing?",
        "a": "A 6213-ZZ-NTN deep-groove ball bearing has a 65 mm bore, 120 mm outer diameter and 23 mm width (2.559 × 4.724 × 0.906 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 6213-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 6200 compare with other series at the same 65 mm bore?",
        "a": "The '2' is the light diameter series: 120×23 mm with a 27.5 mm radial section at 65 mm bore. A 6313 on the same bore is larger and higher-rated; a 6013 is smaller and lower-rated."
      },
      {
        "q": "What is the NTN suffix for a sealed 6213?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6213ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 65×120×23 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6213ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6213-2RS",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6213-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "213",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "213-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×120×23 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6213-zz",
      "6213zz",
      "6213-ZZ",
      "6213ZZ",
      "6213-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6313-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6313",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 103,
    "static_load_kN": 60,
    "fatigue_load_limit_kN": 4.6,
    "limiting_speed_rpm": 4900,
    "max_rpm": 4900,
    "weight_g": 2080,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6313 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 13 by five gives the 65 mm bore; the 140 mm outside diameter and 33 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 65 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "industrial fans",
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Interference on a 65 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6313 with C3 clearance and re-check the residual value after mounting.",
      "The 63xx medium series gains rating at 65 mm bore through a 140 mm OD and 33 mm width; the heavier rolling elements also trade away some speed versus a 6213.",
      "The open 6313-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 65×140×33 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 6300-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6313 units.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 6300-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Measure the shaft, do not trust the drawing: a 65 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6313-NTN.",
      "The open 6313 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 65 mm bore 6313 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4900 r/min for 6313; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "At 103 kN dynamic load rating (C) and 60 kN static (C0), 4.6 kN fatigue load limit Cu, 6313 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 2080 g (2.1 kg), 6313 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 65×140×33 mm envelope of 6313 gives a D/d ratio of 2.15 and 37.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 103/60 kN load ratings, 4.6 kN fatigue load limit Cu NTN lists the grease limiting speed at 4900 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 2080 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6313 on the 65×140×33 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6313 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6313-NTN bearing?",
        "a": "A 6313-NTN deep-groove ball bearing has a 65 mm bore, 140 mm outer diameter and 33 mm width (2.559 × 5.512 × 1.299 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How should 6313-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 65 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 6313-NTN need?",
        "a": "The open 6313-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "What is the NTN order number for an open 6313?",
        "a": "NTN lists the open 6313 under the bare designation 6313; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 65 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6313 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6313 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6313-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "313",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "313-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6313",
      "6313-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6313-2RS-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6313LLU",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "2RS",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 103,
    "static_load_kN": 60,
    "fatigue_load_limit_kN": 4.6,
    "limiting_speed_rpm": 3300,
    "max_rpm": 3300,
    "weight_g": 2080,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6313 carries bore code 13 = 65 mm. Outside diameter 140 mm and width 33 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 65 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's contact-seal catalogue number is 6313LLU (suffix LLU, or LLH low-torque variant), mapped here from the industry-neutral -2RS spelling; the contacting lip lowers the speed ceiling versus the open bearing.",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "seal-lip hardening and loss of pre-grease in sustained high-temperature service",
      "grease-life expiry in the sealed-for-life cavity (no relubrication path)",
      "edge loading from shaft deflection or housing misalignment",
      "rolling-contact fatigue spalling after the rated L10 life is exceeded"
    ],
    "pitfalls": [
      "Interference on a 65 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6313 with C3 clearance and re-check the residual value after mounting.",
      "The 63xx medium section at 65 mm bore gains dynamic rating through larger rolling elements on a 140 mm OD; the penalty is mass and a lower limiting speed than the 6213 — do not specify it for speed-critical shafts.",
      "Heat is the enemy of the sealed 6313-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.",
      "Never wash a sealed 6313-2RS-NTN in solvent or press it home via the outer ring; solvent destroys the grease thickener and mounting force through the seal deforms the lip.",
      "Deep-groove ball bearings tolerate only minutes of misalignment; if the 140 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6313-2RS-NTN.",
      "Vibration during standstill brinells the raceways of a 65 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.",
      "NTN catalogues the contact-sealed version as 6313LLU (suffix LLU), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.",
      "At 65 mm bore 6313 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 3300 r/min for 6313; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "At 103 kN dynamic load rating (C) and 60 kN static (C0), 4.6 kN fatigue load limit Cu, 6313 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 2080 g (2.1 kg), 6313 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 65×140×33 mm envelope of 6313 gives a D/d ratio of 2.15 and 37.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 103/60 kN load ratings, 4.6 kN fatigue load limit Cu NTN lists the grease limiting speed at 3300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 2080 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6313LLU on the 65×140×33 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6313 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6313 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6313-2RS-NTN bearing?",
        "a": "A 6313-2RS-NTN deep-groove ball bearing has a 65 mm bore, 140 mm outer diameter and 33 mm width (2.559 × 5.512 × 1.299 in), per ISO 15 boundary dimensions. It is fitted with two contact rubber seals and is normally pre-greased."
      },
      {
        "q": "Are 6313 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6313 uses the same ISO 15 envelope (65×140×33 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What internal clearance does 6313-2RS-NTN have?",
        "a": "Unless a clearance suffix says otherwise, 6313-2RS-NTN is manufactured to normal (CN) radial internal clearance. Tight fits and hot shafts consume clearance in service — for those conditions order the C3 execution of 6313 and verify the residual clearance after mounting."
      },
      {
        "q": "What is the NTN suffix for a sealed 6313?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6313LLU), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 65×140×33 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6313LLU?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6313-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-2RS",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "313",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "313-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6313-llu",
      "6313llu",
      "6313-2RS",
      "6313-2rs",
      "6313LLU",
      "6313-2RS-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6313-RSR-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6313LLB",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "RSR",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 103,
    "static_load_kN": 60,
    "fatigue_load_limit_kN": 4.6,
    "limiting_speed_rpm": 4900,
    "max_rpm": 4900,
    "weight_g": 2080,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6313 carries bore code 13 = 65 mm. Outside diameter 140 mm and width 33 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 65 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6313LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "ingress of fine dust or moisture past the non-contact lip in dirty or wet duty (RSR is not liquid-tight)",
      "lip-lubricant starvation if the bearing runs dry for extended periods",
      "fretting corrosion on a loose shaft seat",
      "cage damage from operation beyond the limiting speed"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 65 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6313 with C3 for those conditions.",
      "The 63xx medium series gains rating at 65 mm bore through a 140 mm OD and 33 mm width; the heavier rolling elements also trade away some speed versus a 6213.",
      "The low-drag lip of 6313-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.",
      "The non-contact lip of 6313-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 65 mm bore position before relying on it as sealed-for-life.",
      "Measure the shaft, do not trust the drawing: a 65 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 6313-RSR-NTN.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "NTN catalogues this low-friction non-contact seal as 6313LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).",
      "At 65 mm bore 6313 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4900 r/min for 6313; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "At 103 kN dynamic load rating (C) and 60 kN static (C0), 4.6 kN fatigue load limit Cu, 6313 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 2080 g (2.1 kg), 6313 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 65×140×33 mm envelope of 6313 gives a D/d ratio of 2.15 and 37.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 103/60 kN load ratings, 4.6 kN fatigue load limit Cu NTN lists the grease limiting speed at 4900 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 2080 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6313LLB on the 65×140×33 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6313 in a rated drive.",
      "Order the C3 internal-clearance version (6313 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6313 is listed."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6313-RSR-NTN bearing?",
        "a": "A 6313-RSR-NTN deep-groove ball bearing has a 65 mm bore, 140 mm outer diameter and 33 mm width (2.559 × 5.512 × 1.299 in), per ISO 15 boundary dimensions. It is fitted with two low-friction non-contact rubber seals."
      },
      {
        "q": "How does the 6300 compare with other series at the same 65 mm bore?",
        "a": "The '3' is the medium diameter series: 140×33 mm, 37.5 mm radial section at 65 mm bore, carrying more load than a 6213 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "Are 6313 bearings from different brands interchangeable?",
        "a": "For boundary dimensions, yes: every brand's 6313 uses the same ISO 15 envelope (65×140×33 mm). Load ratings, limiting speeds, clearance, precision class and sealing design can differ, so verify those in the supplier catalogue when substituting. Seal suffixes also differ by brand (2RS, DDU, LLU, 2RSL and similar)."
      },
      {
        "q": "What is the NTN suffix for a sealed 6313?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6313LLB), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 65×140×33 mm ISO 15 envelope."
      },
      {
        "q": "Is 6313LLB a current NTN production size?",
        "a": "The NTN 2203-series catalogue lists it as a standard size; availability of specific seal executions (ZZ, LLB/LLF, LLH, LLU) varies by region and stock — confirm with an NTN distributor before specifying spares."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6313-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-RSR",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "313",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "313-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6313-llb",
      "6313llb",
      "6313-RSR",
      "6313-rsr",
      "6313LLB",
      "6313-RSR-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6313-ZZ-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6313ZZ",
    "series": "6300-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 140,
    "B_mm": 33,
    "material": "GCr15",
    "seal_type": "ZZ",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 103,
    "static_load_kN": 60,
    "fatigue_load_limit_kN": 4.6,
    "limiting_speed_rpm": 4900,
    "max_rpm": 4900,
    "weight_g": 2080,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6313-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 13 by five gives the 65 mm bore; the 140 mm outside diameter and 33 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 65 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. NTN catalogue order number: 6313ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.",
    "applications": [
      "industrial electric motors",
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives"
    ],
    "failure_modes": [
      "fine-particle abrasion when non-contact shields let dust past in dirty duty",
      "grease aging in the shield-for-life cavity with no relubrication path",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "Temperature rise and interference fits consume internal clearance on this 65 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6313 with C3 for those conditions.",
      "The 63xx medium series gains rating at 65 mm bore through a 140 mm OD and 33 mm width; the heavier rolling elements also trade away some speed versus a 6213.",
      "ZZ shields are non-contact: 6313-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6313-2RS for that.",
      "Do not wash 6313-ZZ-NTN in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.",
      "Never mix components between two 6313-ZZ-NTN units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 33 mm-wide ring of 6313-ZZ-NTN drags the lip and overheats it.",
      "NTN catalogues the shielded version as 6313ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.",
      "At 65 mm bore 6313 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4900 r/min for 6313; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "At 103 kN dynamic load rating (C) and 60 kN static (C0), 4.6 kN fatigue load limit Cu, 6313 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 2080 g (2.1 kg), 6313 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 65×140×33 mm envelope of 6313 gives a D/d ratio of 2.15 and 37.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 103/60 kN load ratings, 4.6 kN fatigue load limit Cu NTN lists the grease limiting speed at 4900 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 2080 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6313ZZ on the 65×140×33 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6313 in a rated drive.",
      "Order the C3 internal-clearance version (6313 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6313-ZZ-NTN bearing?",
        "a": "A 6313-ZZ-NTN deep-groove ball bearing has a 65 mm bore, 140 mm outer diameter and 33 mm width (2.559 × 5.512 × 1.299 in), per ISO 15 boundary dimensions. It is fitted with two non-contact metallic shields."
      },
      {
        "q": "What does the ZZ suffix on 6313-ZZ mean?",
        "a": "ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing."
      },
      {
        "q": "How does the 6300 compare with other series at the same 65 mm bore?",
        "a": "The '3' is the medium diameter series: 140×33 mm, 37.5 mm radial section at 65 mm bore, carrying more load than a 6213 but needing a larger housing bore and giving up some speed."
      },
      {
        "q": "What is the NTN suffix for a sealed 6313?",
        "a": "NTN uses suffix LLU for the contact rubber seal (catalogue number 6313ZZ), LLB/LLF for non-contact rubber seals, LLH for the low-torque contact seal and ZZ for steel shields. The industry-neutral spellings on this page (-2RS / -RSR / -ZZ) map to those NTN suffixes while keeping the 65×140×33 mm ISO 15 envelope."
      },
      {
        "q": "What cage does NTN fit in 6313ZZ?",
        "a": "Standard is a pressed-steel cage with no suffix; larger sizes or shock-loaded duty can be supplied with a machined brass cage (suffix M) as a separate order number. The catalogue figures quoted here are for the pressed-steel execution."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6313-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-RSR",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-ZZ-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-ZZ",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6313-M",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "313",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "313-ZZ",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 65×140×33 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6313-zz",
      "6313zz",
      "6313-ZZ",
      "6313ZZ",
      "6313-ZZ-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "6413-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6413",
    "series": "6400-series",
    "type": "deep_groove",
    "d_mm": 65,
    "D_mm": 160,
    "B_mm": 37,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 123,
    "static_load_kN": 72.5,
    "fatigue_load_limit_kN": 5.35,
    "limiting_speed_rpm": 4400,
    "max_rpm": 4400,
    "weight_g": 3300,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "6413 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the heavy 64xx section (diameter series 4 of ISO 15), multiplying bore code 13 by five gives the 65 mm bore; the 160 mm outside diameter and 37 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 65 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "centrifugal and positive-displacement pumps",
      "gearboxes and speed reducers",
      "conveyor drives",
      "material-handling equipment"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "brinelling from static overload or hammering during mounting",
      "false brinelling from vibration while the shaft is stationary"
    ],
    "pitfalls": [
      "Interference on a 65 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6413 with C3 clearance and re-check the residual value after mounting.",
      "The 64xx heavy section at 65 mm bore (160 mm OD) is built for high-load, lower-speed duty; specifying it in a high-rpm motor gives excess heat and short grease life — use 62/63 there.",
      "The open 6413-NTN has no lubricant retention: grease escapes and contaminants migrate straight into the 65×160×37 mm raceway, so specify a sealed arrangement for dusty or washdown duty.",
      "Open bearings tolerate the highest speeds in the 6400-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6413 units.",
      "Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.",
      "Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 37 mm-wide ring of 6413-NTN drags the lip and overheats it.",
      "The open 6413 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 65 mm bore 6413 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "NTN lists the grease limiting speed at 4400 r/min for 6413; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.",
      "At 123 kN dynamic load rating (C) and 72.5 kN static (C0), 5.35 kN fatigue load limit Cu, 6413 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.",
      "At 3300 g (3.3 kg), 6413 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.",
      "The 65×160×37 mm envelope of 6413 gives a D/d ratio of 2.46 and 47.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.",
      "The 123/72.5 kN load ratings, 5.35 kN fatigue load limit Cu NTN lists the grease limiting speed at 4400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 3300 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6413 on the 65×160×37 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6413 in a rated drive.",
      "NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.",
      "Standard catalogue stock of 6413 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 6413-NTN bearing?",
        "a": "A 6413-NTN deep-groove ball bearing has a 65 mm bore, 160 mm outer diameter and 37 mm width (2.559 × 6.299 × 1.457 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "What does no suffix on 6413 mean?",
        "a": "A bare 6413 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication."
      },
      {
        "q": "How does the 6400 compare with other series at the same 65 mm bore?",
        "a": "The '4' is the heavy diameter series: 160×37 mm, 47.5 mm radial section at 65 mm bore — the highest-capacity single-row 6xx option here, aimed at lower-speed, high-load shafts."
      },
      {
        "q": "What is the NTN order number for an open 6413?",
        "a": "NTN lists the open 6413 under the bare designation 6413; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 65 mm bore envelope."
      },
      {
        "q": "Does NTN offer 6413 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6413 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "6413-ZZ",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 65×160×37 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6413-2RS",
        "equiv_brand": "GENERIC-ISO",
        "level": "partial",
        "note": "Same 65×160×37 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "6413",
        "equiv_brand": "SKF",
        "level": "full",
        "note": "Same 65×160×37 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6413",
      "6413-NTN"
    ],
    "locale_variants": {}
  },
  {
    "sku": "61814-NTN",
    "brand": "NTN",
    "manufacturer_designation": "6814",
    "series": "61800-series",
    "type": "deep_groove",
    "d_mm": 70,
    "D_mm": 90,
    "B_mm": 10,
    "material": "GCr15",
    "seal_type": "open",
    "clearance": "CN",
    "tolerance_class": "P0",
    "cage_type": "steel_stamped_J",
    "dynamic_load_kN": 13.4,
    "static_load_kN": 11.9,
    "fatigue_load_limit_kN": 0.8,
    "limiting_speed_rpm": 6900,
    "max_rpm": 6900,
    "weight_g": 137,
    "weight_estimated": false,
    "temp_min_c": -40,
    "temp_max_c": 120,
    "standard": "ISO 15",
    "naming_rule_text": "In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61814 carries bore code 14 = 70 mm. Outside diameter 90 mm and width 10 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 70 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).",
    "applications": [
      "space-constrained gearboxes",
      "clutch and transmission assemblies",
      "robotics and automation joints",
      "lay shafts and idler shafts"
    ],
    "failure_modes": [
      "contamination wear from dust and dirt ingress through the open arrangement",
      "lubricant starvation when no regreasing interval is maintained",
      "cage damage from operation beyond the limiting speed",
      "electrical pitting in VFD-driven motors without grounding protection"
    ],
    "pitfalls": [
      "At 70 mm bore, induction heating to roughly 80–100 °C is the clean mounting method; never exceed 120 °C, and hold 61814 against the shaft shoulder while it cools so the ring cannot creep back.",
      "The 618xx thin section at 70 mm bore has only a 10.0 mm radial section height: it saves space but is highly sensitive to misalignment, shaft deflection and shock loads — verify shaft stiffness before choosing it over a 6214.",
      "Storage matters for open bearings: 61814-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.",
      "Open bearings tolerate the highest speeds in the 61800-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61814 units.",
      "Grease compatibility is not guaranteed between fills: mixing lithium and polyurea thickeners in a 61800-series position can soften the mixture and leak — clean out the old fill before switching grease types.",
      "Shaft and housing fillets must clear the bearing chamfer so the 10 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.",
      "The open 61814 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.",
      "At 70 mm bore 61814 is in NTN's upper general-purpose range; the pressed-steel cage is standard but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NTN channel if the application sees impact loads.",
      "At 6900 r/min the grease limiting speed for 61814 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.",
      "NTN rates 61814 at 13.4 kN dynamic (C) and 11.9 kN static (C0), 0.8 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.",
      "At 137 g, 61814 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.",
      "The 70×90×10 mm envelope of 61814 gives a D/d ratio of 1.29 and only 10.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.",
      "The 13.4/11.9 kN load ratings, 0.8 kN fatigue load limit Cu NTN lists the grease limiting speed at 6900 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 137 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6814 on the 70×90×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61814 in a rated drive.",
      "Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.",
      "Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor."
    ],
    "faq": [
      {
        "q": "What are the dimensions of a 61814-NTN bearing?",
        "a": "A 61814-NTN deep-groove ball bearing has a 70 mm bore, 90 mm outer diameter and 10 mm width (2.756 × 3.543 × 0.394 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields."
      },
      {
        "q": "How should 61814-NTN be mounted?",
        "a": "Apply the mounting force to the ring being fitted: on a 70 mm shaft seat the press load must pass through the inner-ring face only. Induction heating of the inner ring (max 120 °C) is the clean method at this size. Never strike the outer ring, the cage or the seals."
      },
      {
        "q": "What lubrication does 61814-NTN need?",
        "a": "The open 61814-NTN is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval."
      },
      {
        "q": "What is the NTN order number for an open 61814?",
        "a": "NTN lists the open 61814 under the bare designation 6814; protected versions use suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal) on the same 70 mm bore envelope."
      },
      {
        "q": "Does NTN offer 61814 with C3 clearance?",
        "a": "Yes — most NTN deep-groove sizes can be ordered with C3 internal clearance (suffix C3 follows the seal code). C3 suits tight fits and hot shafts; for normal fits at moderate temperature the standard CN clearance of 6814 is the correct choice."
      }
    ],
    "cross_ref": [
      {
        "equiv_sku": "61814-2RS-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 70×90×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61814-RSR-NSK",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 70×90×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61814-ZZ",
        "equiv_brand": "NSK",
        "level": "partial",
        "note": "Same 70×90×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61814-NSK",
        "equiv_brand": "NSK",
        "level": "full",
        "note": "Same 70×90×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61814",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×90×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61814-2RS",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×90×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      },
      {
        "equiv_sku": "61814-RSR",
        "equiv_brand": "SKF",
        "level": "partial",
        "note": "Same 70×90×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting."
      }
    ],
    "source_ref": "https://www.ntnglobal.com/en/products/catalog/pdf/2203E_b02.pdf#page=7",
    "catalog_ver": "NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)",
    "extracted_at": "2026-09-25",
    "last_verified": "2026-09-25",
    "confidence_score": 0.7,
    "status": "published",
    "aliases": [
      "6814",
      "61814",
      "61814-NTN"
    ],
    "locale_variants": {}
  }
]